chemistrystudy: Name Reactions

Condensation Reactions

<div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="margin-left: 1em; margin-right: 1em; text-align: center;"><b><span style="font-size: x-large;">Condensation Reactions</span></b></div><br /><h3><b><span style="font-size: large;">Reactive Sites of the Carbonyl Group</span></b></h3><img align="BOTTOM" alt="Condensation Reactions" naturalsizeflag="0" src="http://web.pdx.edu/~wamserc/CH332W97/11gifs/11a.gif" title="Condensation Reactions" /><br /><h4><b>Enols<a name="more"></a></b></h4><ul><li>tautomers - constitutional isomers that are easily interconverted<br />enol structure vs. carbonyl (keto) structure differs by location of one H (and double bond)<br /><img align="BOTTOM" alt="Enols" naturalsizeflag="3" src="http://web.pdx.edu/~wamserc/CH332W97/11gifs/11d.gif" title="Enols" /></li><li>most carbonyl and carboxyl compounds are in equilibrium with just small amounts of enol</li><li>enol form is favored only in special cases if the C=C double bond or the O-H group is specially stabilized<br /><img align="BOTTOM" alt="Enols" naturalsizeflag="3" src="http://web.pdx.edu/~wamserc/CH332W97/11gifs/11e.gif" title="Enols" /><br />cyclohexanone (1 enol per million ketone molecules)<br /><br /><img align="BOTTOM" alt="Enols" naturalsizeflag="3" src="http://web.pdx.edu/~wamserc/CH332W97/11gifs/11f.gif" title="Enols" /><br />24% 2,4-pentanedione : 76% 4-hydroxy-3-penten-2-one</li><li>knowing the right keto-enol forms for the nucleic acid bases allowed Watson and Crick to develop the double-helix concept for DNA<br /><img align="BOTTOM" alt="Enols" naturalsizeflag="3" src="http://web.pdx.edu/~wamserc/CH332W97/11gifs/11g.gif" title="Enols" /><br />guanine (keto form - as in DNA) // guanine (enol form - aromatic but less stable)</li></ul><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/proxy/AVvXsEhBl75-EAqKsS6Nvza_ubmTWfj5yR4NocDqBmJD6qT6_IXsqOoFJ9nud8AIdKG8wqO-vFBUH58N8Mg_GVxOr6DTtn9-G0LZmrXYAXtg9rM-awtMEowFTDH1NdPhDKfSBl7T1e9l2A1RuTLIKx1qGRoRa-T6=" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img align="BOTTOM" alt="Enols" border="0" naturalsizeflag="3" src="http://web.pdx.edu/~wamserc/CH332W97/11gifs/11h.gif" title="Enols" /></a></div><b><br /></b><h4><b>Acid- and Base-Catalyzed Enolization</b></h4><h4><b>Alpha-Substitution on Enols</b></h4><ul><li>enols behave like C=C double bonds - react with electrophiles<br />the net reaction is alpha-substitution</li></ul><img align="BOTTOM" alt="Enols" naturalsizeflag="3" src="http://web.pdx.edu/~wamserc/CH332W97/11gifs/11i.gif" title="Enols" /><br /><b><br /></b><h4><b>Enolate Anions</b></h4><br /><ul><li>carbonyl compounds have pKa values about 20</li><li>strong bases can deprotonate carbonyl compounds</li></ul><img align="BOTTOM" alt="Enolate Anions" naturalsizeflag="3" src="http://web.pdx.edu/~wamserc/CH332W97/11gifs/11j.gif" title="Enolate Anions" /><br /><ul><li>two carbonyl groups increases the acidity further<br />pKa of 1,3-diketones is about 9</li></ul><img align="BOTTOM" alt="Enolate Anions" naturalsizeflag="3" src="http://web.pdx.edu/~wamserc/CH332W97/11gifs/11k.gif" title="Enolate Anions" /><br /><ul><li>enolates are good nucleophiles</li><li>enolates are ambident (two-toothed) nucleophiles<br />usually they react at the C rather than the O anion site<br /><img align="BOTTOM" alt="Enolate Anions" naturalsizeflag="3" src="http://web.pdx.edu/~wamserc/CH332W97/11gifs/11l.gif" title="Enolate Anions" /></li></ul><h4><b>The Aldol Condensation</b></h4><div><img align="BOTTOM" alt="The Aldol Condensation" height="95" naturalsizeflag="3" src="http://web.pdx.edu/~wamserc/CH332W97/11gifs/11o.gif" style="text-align: center;" title="The Aldol Condensation" width="359" /></div><ul><li>reaction of an enolate as nucleophile with a carbonyl group,<br />usually from the same compound</li></ul><img align="BOTTOM" alt="The Aldol Condensation" naturalsizeflag="3" src="http://web.pdx.edu/~wamserc/CH332W97/11gifs/11n.gif" title="The Aldol Condensation" /><br /><ul><li>the reaction is a reversible equilibrium<br />favored towards product (aldol) only for simple aldehydes<br />greater substitution favors starting compounds at equilibrium</li></ul><h4><b>Dehydration</b></h4><ul><li>the aldol reaction is often combined with dehydration of the initial aldol product, forming a conjugated double bond (an enone)</li></ul><img align="BOTTOM" alt="Dehydration" naturalsizeflag="3" src="http://web.pdx.edu/~wamserc/CH332W97/11gifs/11p.gif" title="Dehydration" /><br /><ul><li>base-catalyzed elimination via enolate anion (loss of OH-)</li><li>acid-catalyzed elimination via enol (allylic cation intermediate)</li></ul><h4><b>Other Aldol Combinations<a href="https://www.blogger.com/null" name="more"></a></b></h4><ul><li>crossed aldol reaction - two different carbonyl compounds<br />works best of one has no alpha-hydrogens, e.g., formaldehyde or benzaldehyde</li><li>intramolecular aldol - dicarbonyl compound gives cyclic product</li><li>directed aldol - crossed aldol with one enolate formed in advance</li></ul><h4><b>Kinetic vs. Thermodynamic Control</b></h4><ul><li>ketones often can give two different enolate ions - need to control regioselectivity</li><li>more stable enolate (or enol) is the more substituted (thermodynamically favored)</li><li>more rapidly formed enolate is the less substituted (kinetically favored)</li><li>LiN(iPr)2 ( LDA ) irreversibly removes an alpha H from less-substituted side</li><li>to form kinetic enolate, avoid excess ketone (equilibration can occur)</li></ul><h4><b><a href="http://forum-chemistry.blogspot.com/2014/08/claisen-condensationngung-tu-claisen.html" target="_blank">The Claisen Condensation</a></b></h4><ul><li>condensation with a carboxyl derivative gives substitution instead of addition</li><li>the Claisen condensation gives beta-ketoesters</li></ul><img align="BOTTOM" alt="The Claisen Condensation" height="267" naturalsizeflag="3" src="http://web.pdx.edu/~wamserc/CH332W97/11gifs/11q.gif" title="The Claisen Condensation" width="447" /><br /><ul><li>crossed Claisen reaction - two different esters<br />works best of one has no alpha-hydrogens,<br />e.g., formate, carbonate, oxalate, or benzoate ester</li><li>Dieckmann condensation - intramolecular Claisen - diester gives cyclic product</li></ul><h4><b>Decarboxylation of beta-ketoacids</b></h4><ul><li>Claisen products can be easily hydrolyzed and decarboxylated</li></ul><h4><b>Enamines</b></h4><ul><li>N analog of enols</li><li>formed from 2° amines plus carbonyl compounds</li></ul><img align="BOTTOM" alt="Enamines" border="0" height="76" naturalsizeflag="3" src="http://web.pdx.edu/~wamserc/C335W99/gifs/18b.gif" title="Enamines" width="259" /><br /><ul><li>the N lone pair makes the alpha position electron rich (nucleophilic)</li><li>enamines react with alkyl halides (alkylation) or acyl halides (acylation)</li><li>after hydrolysis, the carbonyl group is reformed</li></ul><h4><b>Acetoacetic Ester and Malonic Ester Syntheses</b></h4><ul><li>methods for preparing substituted acetones or acetic acids</li></ul><img align="BOTTOM" alt="Acetoacetic Ester and Malonic Ester Syntheses" border="0" height="175" naturalsizeflag="3" src="http://web.pdx.edu/~wamserc/C335W99/gifs/18c.gif" title="Acetoacetic Ester and Malonic Ester Syntheses" width="384" /><br /><ul><li>if steps 1) and 2) are repeated, two substituents can be attached</li></ul><h4><b>Michael ( Conjugate or 1,4 ) Addition</b></h4><ul><li>addition of a carbon nucleophile (such as an enolate or enamine)<br />to the beta-position of a conjugated a,b-unsaturated carbonyl compound,<br />creating another enolate anion</li></ul><img align="BOTTOM" alt="Michael " border="0" naturalsizeflag="3" src="http://web.pdx.edu/~wamserc/C335W99/gifs/18d.gif" title="Michael " /><br /><ul><li>Gilman reagents also do conjugate addition</li><li>organolithium and Grignard reagents usually do direct carbonyl addition ( 1,2 addition )<br />these are rapid, irreversible additions under kinetic control</li><li>conjugate addition products (addition to C=C rather than to C=O) are more stable</li></ul><h4><b>Other Related Condensation Reactions</b></h4><ul><li>alpha-anions (nucleophiles) can be made next to any good electron-withdrawing group<br />e.g., nitromethane </li><li>these anions can react with carbonyl compounds to give addition<br />or with carboxyl compounds to give substitution</li></ul><h4><b>Biological Aldol and Claisen Reactions</b></h4><ul><li>acetyl Co-A often acts as a biological nucleophile at its alpha-position</li><li>formation of acetoacetyl Co-A is the first step in building up fatty acids</li></ul><img align="BOTTOM" alt="Biological Aldol and Claisen Reactions" border="0" naturalsizeflag="3" src="http://web.pdx.edu/~wamserc/C335W99/gifs/18a.gif" title="Biological Aldol and Claisen Reactions" /><br />aldolase is an enzyme that adds dihydroxyacetone to glyceraldehyde to form fructose<br />two 3-carbon sugars join to become a 6-carbon sugar<br /><br /><div><span style="color: red; font-size: large;">(Nguồn: http://web.pdx.edu/~wamserc/C335W00/18notes.htm)</span></div><br />

Condensation Reactions

Condensation Reactions Reactive Sites of the Carbonyl Group Enols tautomers - constitutional isomers that are easily interconverted enol str...

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Mechanism of the Claisen Condensation

Unknown 0 Claisen Condensation, Name Reactions, ngưng tụ claisen 20:28

<h2><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiFdBbJHxNA6dpU1TQLpTMmmLmgBiDNSKbxqQ1M3-t0jEOlzAEpmNqe278I9VCYeQYajLGN4RWDIZOb1MLIghv41nq1ACkt4swGjj3cxLDCQ90DhVsX6QLnsHIzaDN8iFbEhxf0TemnyXA/s1600/claisen.gif" imageanchor="1" style="font-size: medium; font-weight: normal; margin-left: 1em; margin-right: 1em; text-align: center;"><img alt="Mechanism of the Claisen Condensation" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiFdBbJHxNA6dpU1TQLpTMmmLmgBiDNSKbxqQ1M3-t0jEOlzAEpmNqe278I9VCYeQYajLGN4RWDIZOb1MLIghv41nq1ACkt4swGjj3cxLDCQ90DhVsX6QLnsHIzaDN8iFbEhxf0TemnyXA/s1600/claisen.gif" title="Mechanism of the Claisen Condensation" /></a></h2><h2><i style="font-family: Arial, Helvetica, 'sans serif';"><span style="font-size: large;">Mechanism of the Claisen Condensation</span></i></h2><h3><b><i>Reaction type : Nucleophilic Acyl Substitution<a name="more"></a></i></b></h3><div><h4>Summary</h4><ul><li>The Claisen condensation is the ester analogue of the Aldol condensation.</li><li>Reagents : most commonly the base would be the alkoxide, <b>R'O<sup>-</sup></b></li><li>The reaction involves an ester enolate reacting with another molecule of the ester.</li><li>Remember enolates are good nucleophiles and the ester carbonyl <b>C</b> are electrophilic.</li><li>The products of these reactions are <b><i><span style="font-family: Symbol;">b-</span>ketoesters</i></b> which are important, useful synthetic intermediates.</li><li>Note that the product is the original ester with an <b>acyl<span style="color: #3333ff;"> </span></b>group added <i>i.e.</i> an <b>acylation</b> reaction has occurred.</li><li>A simple example of a <b><i>Claisen condensation </i></b>is the reaction of ethyl ethanoate which is shown below in two representations:</li></ul></div><div><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgRvroNWaiQqc0BfEoj5ZrHmV1qlVqm9h4IisnLrQsue59e9_6ME7BJdS5Zqdl9Fmj-j2gycZknUjwJ26yJxP1UwwgyXjcQm58X8fOcHo_Tvi6Z87SORWYbWM_dkAwdOnPdOmWg37waCIU/s1600/claisenmech.gif" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img alt="Mechanism of the Claisen Condensation" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgRvroNWaiQqc0BfEoj5ZrHmV1qlVqm9h4IisnLrQsue59e9_6ME7BJdS5Zqdl9Fmj-j2gycZknUjwJ26yJxP1UwwgyXjcQm58X8fOcHo_Tvi6Z87SORWYbWM_dkAwdOnPdOmWg37waCIU/s1600/claisenmech.gif" title="Mechanism of the Claisen Condensation" /></a></div><div><b style="background-color: white; font-family: Arial;"><br /></b></div><div><b style="background-color: white; font-family: Arial;"><br /></b></div><div><b style="background-color: white; font-family: Arial;">Step 1:</b><span style="background-color: white; font-family: Arial;"> </span><br /><span style="background-color: white; font-family: Arial;">First, an acid-base reaction. The alkoxide functions as a base and removes the acidic </span><span style="background-color: white; font-family: Symbol;">a</span><span style="background-color: white; font-family: Arial;">-hydrogen giving the reactive ester enolate</span></div><div><span style="background-color: white; font-family: Arial;"><br /></span></div><div><span style="background-color: white; font-family: Arial;"><br /></span></div><div><b style="background-color: white; font-family: Arial;">Step 2:</b><span style="background-color: white; font-family: Arial;"> </span><br /><span style="background-color: white; font-family: Arial;">The nucleophilic ester enolate attacks the carbonyl </span><b style="background-color: white; font-family: Arial;">C</b><span style="background-color: white; font-family: Arial;"> of another ester in a </span><a href="http://www.chem.ucalgary.ca/courses/351/Carey5th/Ch20/ch20-2-1.html" rel="nofollow" style="background-color: white; font-family: Arial;" target="_blank">nucleophilic substitution process</a><span style="background-color: white; font-family: Arial;"> giving the tetrahedral intermediate.</span></div><div><span style="background-color: white; font-family: Arial;"><br /></span></div><div><span style="background-color: white; font-family: Arial;"><br /></span></div><div><span style="background-color: white; font-family: Arial;"><br /></span></div><div><span style="background-color: white; font-family: Arial;"><b>Step 3:</b><br />The intermediate collapses, reforming the <b>C=O</b>, resulting in loss of the leaving group, the alkoxide, leading to the </span><span style="background-color: white; font-family: Symbol;">b</span><span style="background-color: white; font-family: Arial;">-ketoester product.</span></div><div><span style="background-color: white; font-family: Arial;"><br /></span></div><div><span style="background-color: white; font-family: Arial;"><br /></span></div><div><span style="font-family: Arial;"><span style="background-color: white;">(nguồn: </span>http://www.chem.ucalgary.ca/courses/351/Carey5th/Ch21/ch21-3-1.html</span><br /><span style="font-family: Arial;">http://www.mhhe.com/physsci/chemistry/carey/student/olc/graphics/carey04oc/ref/ch21enolatereactions.html)</span><br /><span style="font-family: Arial;"><br /></span><span style="font-family: Arial;"><br /></span><br /><h4><span style="font-family: Arial; font-size: large;"><i>More than:</i></span></h4></div><div><div style="background-color: white;"><span style="font-family: Arial, Helvetica, sans-serif;">The general form of a <a href="http://forum-chemistry.blogspot.com/2014/08/claisen-condensationngung-tu-claisen.html" target="_blank">Claisen condensation</a> is as follows:</span></div><div style="background-color: white;"><span style="font-family: Arial, Helvetica, sans-serif; font-size: x-small;"><br /><img alt="Mechanism of the Claisen Condensation" height="67" src="http://www.chemhelper.com/images/pictures/claisen1.gif" title="Mechanism of the Claisen Condensation" width="344" /></span></div><div style="background-color: white;"><span style="font-family: Arial, Helvetica, sans-serif;">The first step involves adding a strong base to an ester to generate an enolate at the <span style="font-family: Symbol;">a</span> carbon (note that the enolate has an additional resonance structure).</span></div><div style="background-color: white;"><img alt="Mechanism of the Claisen Condensation" height="276" src="http://www.chemhelper.com/images/pictures/claisen2.gif" title="Mechanism of the Claisen Condensation" width="468" /></div><div style="background-color: white;"><span style="font-family: Arial, Helvetica, sans-serif;">The enolate can then add to another ester molecule by attacking the carbonyl to make the tetrahedral intermediate. The carbonyl reforms with loss of the alcoxy group to make the <span style="font-family: Symbol;">b</span>-keto ester.</span></div><div style="background-color: white;"><br /></div><div style="background-color: white;"><h4><span style="font-family: Arial, Helvetica, sans-serif;"><b><i>Example of a Claisen condensation:</i></b></span></h4></div><div style="background-color: white;"><img alt="Mechanism of the Claisen Condensation" height="292" src="http://www.chemhelper.com/images/pictures/dieckmann.gif" title="Mechanism of the Claisen Condensation" width="386" /></div><div style="background-color: white;"><span style="font-family: Arial, Helvetica, sans-serif;">This is an example of an intramolecular Claisen reaction, called a Dieckmann condensation.</span></div><div style="background-color: white;"><span style="font-family: Arial, Helvetica, sans-serif; font-size: x-small;"><br /></span></div><h3 style="background-color: white;"><span style="font-family: Arial, Helvetica, sans-serif; font-size: x-large;"><i>Learn More:</i></span></h3><div><h3><span style="font-family: Arial, Helvetica, sans-serif; font-size: large;"><i><a href="http://forum-chemistry.blogspot.com/2014/08/mechanism-of-claisen-condensation.html" target="_blank">Claisen condensation mechanism</a></i></span></h3></div><div><h4 style="background-color: white; border: 0px; color: #333333; font-family: Arial, Helvetica, sans-serif; line-height: 18px; margin-bottom: 8px !important; margin-top: 0.25em; padding: 0px; visibility: visible;">1) Enolate formation</h4></div><div><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhqCA1Bqlfd4N-eqJVlDQvjlGecMn93w17pMLYxYrvwvUWRhyQakRR6Cfpey0BZABkRvkz5O5eP2SBeDXOG69b4sQ2DompA02Up6Z-A9TjjwyGlLZcYPhcp3qoT5l_HQR4FcILqHz8zUcE/s1600/Claisen+condensation+mechanism.jpg" imageanchor="1" style="clear: left; display: inline !important; margin-bottom: 1em; margin-right: 1em; text-align: center;"><img alt="Mechanism of the Claisen Condensation" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhqCA1Bqlfd4N-eqJVlDQvjlGecMn93w17pMLYxYrvwvUWRhyQakRR6Cfpey0BZABkRvkz5O5eP2SBeDXOG69b4sQ2DompA02Up6Z-A9TjjwyGlLZcYPhcp3qoT5l_HQR4FcILqHz8zUcE/s1600/Claisen+condensation+mechanism.jpg" title="Mechanism of the Claisen Condensation" /></a></div><div><h4 style="background-color: white; border: 0px; color: #333333; font-family: Arial, Helvetica, sans-serif; line-height: 18px; margin-bottom: 8px !important; margin-top: 0.25em; padding: 0px; visibility: visible;">2) Nucleophilic attack</h4></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEikMXxJrVLN_xk94Mmf5Xfel7CGlJUcXtXr1MysQnSshFtw-cdbxVjunMc40PQL6fTUozJ6fJx8G4XXjIbTW5th1IOgN1urn-JAT3izR42LffRpCzmuScmZVpR4hwbabI164Ov5p5VHi-w/s1600/Claisen+condensation+mechanism2.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Mechanism of the Claisen Condensation" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEikMXxJrVLN_xk94Mmf5Xfel7CGlJUcXtXr1MysQnSshFtw-cdbxVjunMc40PQL6fTUozJ6fJx8G4XXjIbTW5th1IOgN1urn-JAT3izR42LffRpCzmuScmZVpR4hwbabI164Ov5p5VHi-w/s1600/Claisen+condensation+mechanism2.jpg" title="Mechanism of the Claisen Condensation" /></a></div><h4 style="background-color: white; border: 0px; color: #333333; font-family: Arial, Helvetica, sans-serif; line-height: 18px; margin-bottom: 8px !important; margin-top: 0.25em; padding: 0px; visibility: visible;">3) Removal of leaving group<span style="background-color: transparent;"> </span></h4><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgZaNkEnkIu_qAZ02xY6apqPvH0TaqO6JORtkfRy0T-RCu06XCA1HTzz44CBoIUBw0K2lqLxWT0dm9ommqUOnFc6Yt-VRV07FUVn5nfpbRZW-PPAOXbJw-1mP_t6HZoDSK9s3lLtxceuHo/s1600/Claisen+condensation+mechanism3.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Mechanism of the Claisen Condensation" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgZaNkEnkIu_qAZ02xY6apqPvH0TaqO6JORtkfRy0T-RCu06XCA1HTzz44CBoIUBw0K2lqLxWT0dm9ommqUOnFc6Yt-VRV07FUVn5nfpbRZW-PPAOXbJw-1mP_t6HZoDSK9s3lLtxceuHo/s1600/Claisen+condensation+mechanism3.jpg" title="Mechanism of the Claisen Condensation" /></a></div><br /></div>

Mechanism of the Claisen Condensation

Mechanism of the Claisen Condensation Reaction type : Nucleophilic Acyl Substitution Summary The Claisen condensation is the ester analogue ...

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Acetoacetic Ester Synthesis-Organic reaction

Unknown 0 Chemistry lesson, Name Reactions, Organic reaction 09:53

<h2 style="text-align: center;"><span style="font-size: x-large;"><span style="color: blue;">Acetoacetic Ester Synthesis</span></span></h2><div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg7X4ErBLAtiEwLzrd_6PC-kkXadhe2c1x0WsJrCx_bQKMUq-xvnPZfi5rqhlKmkGCK6eNIeVckspgJU9YERPYehw2KAO3EWF4AUJ-UK32BuyMjt9Csc-7w1_aAhIZRR9XDlCLxtl0uFPQ/s1600/Acetoacetic+Ester+Synthesis-Organic+reaction.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Acetoacetic Ester Synthesis-Organic reaction-chemistry and creativity" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg7X4ErBLAtiEwLzrd_6PC-kkXadhe2c1x0WsJrCx_bQKMUq-xvnPZfi5rqhlKmkGCK6eNIeVckspgJU9YERPYehw2KAO3EWF4AUJ-UK32BuyMjt9Csc-7w1_aAhIZRR9XDlCLxtl0uFPQ/s1600/Acetoacetic+Ester+Synthesis-Organic+reaction.jpg" title="Acetoacetic Ester Synthesis-Organic reaction-chemistry and creativity" /></a></div><a name="more"></a><br /></div><h3><span style="color: blue; font-size: large;">Acetoacetic ester synthesis<a href="https://www.blogger.com/null" name="more"></a></span></h3>Acetoacetic ester synthesis is a chemical reaction where ethyl acetoacetate is alkylated at the α-carbon to both carbonyl groups and then converted into a ketone, or more specifically an α-substituted acetone. This is very similar to malonic ester synthesis.<br /><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgbCPbQ2SCutEgAlCd2u_fzDAIq2JO2DjomphrJPP8Vpj1YFpueeeF3vYlKlr8f8z_C39Ba1FSgkSdAuX4Is8G37-xZ4-7Jgp4jct3FJwP_B14swBRBpnJtaEPyPPvDRNJhItfF_AXMAJE/s1600/Acetoacetic+Ester+Synthesis-Organic+reaction-chemistry+and+creativity.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Acetoacetic Ester Synthesis-Organic reaction-chemistry and creativity" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgbCPbQ2SCutEgAlCd2u_fzDAIq2JO2DjomphrJPP8Vpj1YFpueeeF3vYlKlr8f8z_C39Ba1FSgkSdAuX4Is8G37-xZ4-7Jgp4jct3FJwP_B14swBRBpnJtaEPyPPvDRNJhItfF_AXMAJE/s1600/Acetoacetic+Ester+Synthesis-Organic+reaction-chemistry+and+creativity.jpg" title="Acetoacetic Ester Synthesis-Organic reaction-chemistry and creativity" /></a></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both;">When α-keto acetic acid is treated with one mole of a base, the methylene group which is more acidic reacts with the base. And the reaction with an alkylation reagent gives alkyl products attached to methylene. When this reaction is repeated in the next step, the other hydrogen can also react to a dialkyl product. The two alkylation agents may be the same or different (R',R'').</div><div class="separator" style="clear: both;"><br /></div><div class="separator" style="clear: both;">β-Keto esters tend to decarboxylate after hydrolysation to β-keto carboxylic acid and heating to give one or two alkyl-substituted ketones, respectively.</div><div class="separator" style="clear: both;"><br /></div><hr align="center" width="80%" /><h3 style="clear: both;"><span style="color: blue; font-size: large;">Mechanism</span></h3>A strong base <b><span style="color: red;">deprotonates</span></b> the dicarbonyl α-carbon. This carbon is preferred over the methyl carbon because the formed enolate is conjugated and thus resonance stabilized. The carbon then undergoes nucleophilic substitution. When heated with aqueous acid, the newly alkylated ester is hydrolyzed to a β-keto acid, which is decarboxylated to form a methyl ketone.<br /><div><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjnLBLju_A2PIUpXbzpGVv362UZ4S9nsgAgPUHVrxKgdA23FIwc9DP-m98XZvV0VTlnaG_brcW7J4XdnSf6VEaw3dtdSNeDKjSizEI2CdZF0pVNe48oBb8G9b16KzFl6vGZozIW0swDvJc/s1600/Acetoacetic+Ester+Synthesis-Organic+reaction.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Acetoacetic Ester Synthesis-Organic reaction" border="0" height="256" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjnLBLju_A2PIUpXbzpGVv362UZ4S9nsgAgPUHVrxKgdA23FIwc9DP-m98XZvV0VTlnaG_brcW7J4XdnSf6VEaw3dtdSNeDKjSizEI2CdZF0pVNe48oBb8G9b16KzFl6vGZozIW0swDvJc/s1600/Acetoacetic+Ester+Synthesis-Organic+reaction.jpg" title="Acetoacetic Ester Synthesis-Organic reaction" width="640" /></a></div><br /><b><span style="color: red;">Deprotonates</span></b> :Deprotonation is the removal of a proton (H+) from a molecule, forming the conjugate base. The proton removal decreases positive charge in the molecule and an increases negative charge. Deprotonation usually occurs from the donation of electrons or acceptance of the proton using a base, which forms its conjugate acid.<br /><br /><hr align="center" width="80%" /><br /><h3><span style="color: blue; font-size: large;">Mechanism of Acetoacetic Ester Synthesis</span></h3><b><span style="color: red; font-size: large;">Step 1</span></b><br /><br />In the presence of mild base such as NaOH or NaOEt, the alpha – hydrogen of the beta-keto ester can be abstracted to produce the carbanion which can resonate to form an enolate. Since the enolate can resonate on either side of the ester and the ketone it is more stabilized and hence use of even mild bases can be made for this reaction.<br /><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgeqsqEOZG6udwCpuEqTxW4hm2vgl-pPWi9Rxbcx9QY9jWqe_KIvpNBn1E92yyaYBi3HFjSeyeKiP5Ss2Lb2X0RAVGFAcY8TeG3G97cACd1ouCcuMhhbJqmKee3zV4ODcerv0Kihuw4jOQ/s1600/Mechanism+of+Acetoacetic+Ester+Synthesis.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Mechanism of Acetoacetic Ester Synthesis" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgeqsqEOZG6udwCpuEqTxW4hm2vgl-pPWi9Rxbcx9QY9jWqe_KIvpNBn1E92yyaYBi3HFjSeyeKiP5Ss2Lb2X0RAVGFAcY8TeG3G97cACd1ouCcuMhhbJqmKee3zV4ODcerv0Kihuw4jOQ/s1600/Mechanism+of+Acetoacetic+Ester+Synthesis.jpg" title="Mechanism of Acetoacetic Ester Synthesis" /></a></div><div style="text-align: center;">Abstraction of alpha-proton yields a carbanion which is stabilized by enol formation through resonance on either side of beta keto ester</div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhPY2ZU__ma-fjODfQQMbtzSPUYL0_py3X0r9RdDGVSGS-Jt9ZHXs5lVRV_fiw9bXLYFmf5-eNhR94kjU8KVHr6zSs2lh_KKOv5IJMUZDuWbw4Hf5MMdzPODt9-W2Fn122tRGxGcCDv2mg/s1600/Acetoacetic+Ester+Synthesis-Organic+reaction.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Acetoacetic Ester Synthesis-Organic reaction" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhPY2ZU__ma-fjODfQQMbtzSPUYL0_py3X0r9RdDGVSGS-Jt9ZHXs5lVRV_fiw9bXLYFmf5-eNhR94kjU8KVHr6zSs2lh_KKOv5IJMUZDuWbw4Hf5MMdzPODt9-W2Fn122tRGxGcCDv2mg/s1600/Acetoacetic+Ester+Synthesis-Organic+reaction.jpg" title="Acetoacetic Ester Synthesis-Organic reaction" /></a></div><div style="text-align: center;"><br /></div><span style="color: red; font-size: large;"><b>Step 2 and Step 3</b></span><br /><br />The enolate carbanion thus formed is capable of attacking the alkyl halide R-X as the halide is a good leaving group. This yields the mono-alkylated beta-keto ester (i). However, reaction does not stop there. Since the base and alkyl halide are present in the same solution, step 1 and 2 can repeat in step 3 to produce the disubstituted beta-keto ester (ii).<br /><br />Note - For step 2 the carbanion shown below can exist as enolates in resonance structures (as shown above) – hence it can be shown using the illustration below or using enolates but with proper arrows indicating movement of electrons.<br /><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjbDO_XL1h7D5JArHjL4C4SMR8ITmxj_yk08Ux-aG1O09qjm8EE3vj_B5y1QzjUqYxvhkuOlqBm87l-_LgCqiKThpW1fxAP7upHTGeApEUdO05aWaQQBZsRSCMye8yIYanyHVT5rYompD8/s1600/Acetoacetic+Ester+Synthesis-Organic+reaction.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Acetoacetic Ester Synthesis-Organic reaction" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjbDO_XL1h7D5JArHjL4C4SMR8ITmxj_yk08Ux-aG1O09qjm8EE3vj_B5y1QzjUqYxvhkuOlqBm87l-_LgCqiKThpW1fxAP7upHTGeApEUdO05aWaQQBZsRSCMye8yIYanyHVT5rYompD8/s1600/Acetoacetic+Ester+Synthesis-Organic+reaction.jpg" title="Acetoacetic Ester Synthesis-Organic reaction" /></a></div><br /><br /><div style="text-align: center;">Attack of the enolate on the alkyl halide (R-X) to yield mono- and di- alkylated beta keto ester</div><div style="text-align: center;"><br /></div><span style="color: red; font-size: large;"><b>Step 4</b></span><br /><br />Upon acidification of the solution the esters can undergo hydrolysis to yield the acid. Note – this reaction can happen with both mono (as shown) as well as di-substituted beta keto ester (not shown).<br /><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh37h_PIQ_y_EjJf1vivwJu50-n5UoCBlt2ZWmapndVrz0nHpMHdsnr-kBCPkH2UExfLIhKCWc44Ye8MQs1co4EP3uzrY4oe-F-UrX9zqfcLYKtPmR9Q6dcQC8HhsWGxOhdhNn33XbSssQ/s1600/Acetoacetic+Ester+Synthesis-Organic+reaction.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Acetoacetic Ester Synthesis-Organic reaction" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh37h_PIQ_y_EjJf1vivwJu50-n5UoCBlt2ZWmapndVrz0nHpMHdsnr-kBCPkH2UExfLIhKCWc44Ye8MQs1co4EP3uzrY4oe-F-UrX9zqfcLYKtPmR9Q6dcQC8HhsWGxOhdhNn33XbSssQ/s1600/Acetoacetic+Ester+Synthesis-Organic+reaction.jpg" title="Acetoacetic Ester Synthesis-Organic reaction" /></a></div><br /><span style="color: red; font-size: large;"><b>Step 5</b></span><br /><br />Under acidic conditions and slight heating the beta-keto carboxylate can undergo a loss of carbon dioxide to yield either mono (as shown) or disubstituted (not shown) ketone<br /><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhcucDKIvOW_s22ilcovSHn9_AWJlix51VLKsSOmVcT87-aGvbqfsWrr4HrGRXC0EkOEJsKHIIc4T-FbFx3Jk6iexZ8Ow7VvleCOhh-Lr4yCmLDqnVsqI4dI0iyOaUJpQaTedn9dd9TD6k/s1600/Acetoacetic+Ester+Synthesis-Organic+reaction.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Acetoacetic Ester Synthesis-Organic reaction" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhcucDKIvOW_s22ilcovSHn9_AWJlix51VLKsSOmVcT87-aGvbqfsWrr4HrGRXC0EkOEJsKHIIc4T-FbFx3Jk6iexZ8Ow7VvleCOhh-Lr4yCmLDqnVsqI4dI0iyOaUJpQaTedn9dd9TD6k/s1600/Acetoacetic+Ester+Synthesis-Organic+reaction.jpg" title="Acetoacetic Ester Synthesis-Organic reaction" /></a></div><br /><div style="text-align: center;">Under acidic conditions the carboxylic acid can loose one molecule of carbon dioxide to yield the alpha-alkyl ketone.</div><div style="text-align: center;"><br /></div><br /></div><hr align="center" width="80%" /><div><h4><span style="color: blue; font-size: large;"><b>References</b></span></h4><ol><li><a href="http://goo.gl/1TzXY5" target="_blank">Smith, Janice Gorzynski. Organic Chemistry: Second Ed. 2008. pp 905–906</a></li><li><a href="http://pharmaxchange.info/press/2011/02/acetoacetic-ester-synthesis-alkylation-of-enolates/" target="_blank">Acetoacetic Ester Synthesis – Alkylation of Enolates | PharmaXChange.info</a></li></ol><h3><span style="color: blue; font-size: large;">Related Books</span></h3><h4><span style="font-size: large;">1.<a href="http://goo.gl/bovTWx" target="_blank">Organic Chemistry Hardcover . W. Graham Solomons</a></span></h4></div><br /><div class="separator" style="clear: both; text-align: center;"><iframe frameborder="0" marginheight="0" marginwidth="0" scrolling="no" src="//ws-na.amazon-adsystem.com/widgets/q?ServiceVersion=20070822&OneJS=1&Operation=GetAdHtml&MarketPlace=US&source=ac&ref=tf_til&ad_type=product_link&tracking_id=chemistrandcr-20&marketplace=amazon&region=US&placement=1118133579&asins=1118133579&linkId=LIETFKMHHZO4PD5A&show_border=true&link_opens_in_new_window=true" style="height: 240px; width: 120px;"></iframe><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjmL91W5Z16IQu_JSFfS38Tf6-_0orF1SO8tUEceckCfDdm7NlXbJvsVjjwWcFjg-GREi8HWePSks9J7dhZx3usv9419wpwEDgzpgLTsuiASPvpDl1dP2NKyvYywKZIFvb01U3CmGjXfn4/s1600/Organic+Chemistry+Hardcover+T.+W.+Graham+Solomons.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjmL91W5Z16IQu_JSFfS38Tf6-_0orF1SO8tUEceckCfDdm7NlXbJvsVjjwWcFjg-GREi8HWePSks9J7dhZx3usv9419wpwEDgzpgLTsuiASPvpDl1dP2NKyvYywKZIFvb01U3CmGjXfn4/s1600/Organic+Chemistry+Hardcover+T.+W.+Graham+Solomons.jpg" /></a><a href="http://goo.gl/bovTWx" target="_blank"><img alt="buy now" border="0" height="100" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiTQpeTdUkfp4TW2CROEWsG_0LbKbLdJXo7tIxGCeDXSSrpQvB-Qxglp5uGpMI8prT5kEAbr3OItsk2UAck5ABkPHC7WFrZLu10BuEBegqOvYZxTwrffv7GsktKKC-vXrPvIKof9Hg6IFs/s1600/Buy-Now-button.jpg" width="200" /></a></div><span style="text-align: start;"> </span><span style="text-align: start;">Now in a new edition, this book continues its tradition of excellence in teaching and preparing students for success in the organic classroom and beyond. A central theme of the authors' approach to organic chemistry is to emphasize the relationship between structure and reactivity. To accomplish this, the text is organized in a way that combines the most useful features of a functional group approach with one largely based on reaction mechanisms. Emphasizing mechanisms and their common aspects as often as possible, this book shows students what organic chemistry is, how it works, and what it does in living systems and the physical world around us.</span><br /><div class="separator" style="clear: both; text-align: center;"></div><br /><div><h4><span style="color: blue; font-size: large;"> 2.<a href="http://www.amazon.com/gp/product/1118144341/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1118144341&linkCode=as2&tag=chemistrandcr-20&linkId=PJVFDFQQJC6ZN3NV" target="_blank">Organic Chemistry As a Second Language: Second Semester Topics  David R. Klein</a></span></h4><br /><div class="separator" style="clear: both; text-align: center;"><iframe frameborder="0" marginheight="0" marginwidth="0" scrolling="no" src="//ws-na.amazon-adsystem.com/widgets/q?ServiceVersion=20070822&OneJS=1&Operation=GetAdHtml&MarketPlace=US&source=ac&ref=tf_til&ad_type=product_link&tracking_id=chemistrandcr-20&marketplace=amazon&region=US&placement=1118144341&asins=1118144341&linkId=N5SMFEVAYBLGQQBN&show_border=true&link_opens_in_new_window=true" style="height: 240px; width: 120px;"></iframe><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhP2XbGwccs1RrjEPJ7LiYKP3_QIn7Hea4z3BNtV0nkGYf8w-7cCWYaRlmP34UyJnq8ghzL-EQhDRFPNfa4-h72iSwA8zm5SzeCzotK31biBc7ED0mgrR7UXLhEYd_oDaX9A0VUGRHU35M/s1600/Organic+Chemistry+As+a+Second+Language+Second+Semester+Topics+David+R.+Klein.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhP2XbGwccs1RrjEPJ7LiYKP3_QIn7Hea4z3BNtV0nkGYf8w-7cCWYaRlmP34UyJnq8ghzL-EQhDRFPNfa4-h72iSwA8zm5SzeCzotK31biBc7ED0mgrR7UXLhEYd_oDaX9A0VUGRHU35M/s1600/Organic+Chemistry+As+a+Second+Language+Second+Semester+Topics+David+R.+Klein.jpg" /></a><a href="http://www.amazon.com/gp/product/1118144341/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1118144341&linkCode=as2&tag=chemistrandcr-20&linkId=PJVFDFQQJC6ZN3NV" target="_blank"><img alt=" Buy Now" border="0" height="100" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiTQpeTdUkfp4TW2CROEWsG_0LbKbLdJXo7tIxGCeDXSSrpQvB-Qxglp5uGpMI8prT5kEAbr3OItsk2UAck5ABkPHC7WFrZLu10BuEBegqOvYZxTwrffv7GsktKKC-vXrPvIKof9Hg6IFs/s1600/Buy-Now-button.jpg" width="200" /></a></div><div style="text-align: left;"><br /></div><br />Readers continue to turn to Klein because it enables them to better understand fundamental principles, solve problems, and focus on what they need to know to succeed. The third edition explores the major principles in the field and explains why they are relevant. It is written in a way that clearly shows the patterns in organic chemistry so that readers can gain a deeper conceptual understanding of the material. Topics are presented clearly in an accessible writing style along with numerous of hands-on problem solving exercises.<br /><div><h4><b><span style="color: blue; font-size: large;">Related Reactions</span></b></h4></div><div><a href="http://www.organic-chemistry.org/namedreactions/knoevenagel-condensation.shtm"><span style="color: purple;">Knoevenagel Condensation</span></a></div><a href="http://www.organic-chemistry.org/namedreactions/malonic-ester-synthesis.shtm"><span style="color: purple;">Malonic Ester Synthesis</span></a><br /><a href="http://www.organic-chemistry.org/synthesis/C1C/carbonyls/alkylations.shtm"><span style="color: purple;">Synthesis of ketones</span></a><br /><br /><span style="color: purple; font-size: large;"><b>Example</b></span><br /><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjYuobrWYZxURDE4wE3YA6MTly1yTA5GmvsIFRzlMUpcEP0AqBWoTTJ1rcbBZcRGcrCBN1W3irb7A8uSChp101Boc1Y9-bbX36slT0Yqf5WL3JxAIY9y9vu1M6YN5SSJiNGDiHZRGgdfVk/s1600/Acetoacetic+Ester+Synthesis-Organic+reaction1.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Acetoacetic Ester Synthesis-Organic reaction" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjYuobrWYZxURDE4wE3YA6MTly1yTA5GmvsIFRzlMUpcEP0AqBWoTTJ1rcbBZcRGcrCBN1W3irb7A8uSChp101Boc1Y9-bbX36slT0Yqf5WL3JxAIY9y9vu1M6YN5SSJiNGDiHZRGgdfVk/s1600/Acetoacetic+Ester+Synthesis-Organic+reaction1.jpg" title="Acetoacetic Ester Synthesis-Organic reaction" /></a></div><div class="separator" style="clear: both; text-align: center;"><br /></div><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg_oQCbj-Za2uD7JoQP75nQ29sct-lDmAmEbJWegv2jbFuE9uLFNn3vbrD2KEunFYvE7OqwePIIIhLtc_8jecnmDdeYez9KdVMh50U6acoqs-_WEBs7LckrMwM9MYODDwJNiSuUdmsrsVE/s1600/Acetoacetic+Ester+Synthesis-Organic+reaction2.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Acetoacetic Ester Synthesis-Organic reaction" border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg_oQCbj-Za2uD7JoQP75nQ29sct-lDmAmEbJWegv2jbFuE9uLFNn3vbrD2KEunFYvE7OqwePIIIhLtc_8jecnmDdeYez9KdVMh50U6acoqs-_WEBs7LckrMwM9MYODDwJNiSuUdmsrsVE/s1600/Acetoacetic+Ester+Synthesis-Organic+reaction2.jpg" title="Acetoacetic Ester Synthesis-Organic reaction" width="382" /></a></div><br /></div>

Acetoacetic Ester Synthesis-Organic reaction

Acetoacetic Ester Synthesis Acetoacetic ester synthesis Acetoacetic ester synthesis is a chemical reaction where ethyl acetoacetate is alkyl...

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Acyloin Condensation-Organic reaction

Unknown 0 Chemistry lesson, Name Reactions, Organic reaction 09:51

<h2><span style="font-size: x-large;"><span style="color: blue;">Acyloin Condensation-Name reaction</span></span></h2><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhX9KzVGNcrWYb1JiZjEtFgaCE1sJbz3I0dP7ObQOZLl_t3z1N9iYQyfPuZepMVuzvaoW9yMBo9xI-o2AXU9dJQ4r8DZm04w0egAtJCN6Y2i8Mos5QkmIBtFHrtBZTxaO4sHx1wTQrlbL4/s1600/Acetoacetic+Ester+Synthesis-Organic+reaction.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Acyloin Condensation-Organic reaction" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhX9KzVGNcrWYb1JiZjEtFgaCE1sJbz3I0dP7ObQOZLl_t3z1N9iYQyfPuZepMVuzvaoW9yMBo9xI-o2AXU9dJQ4r8DZm04w0egAtJCN6Y2i8Mos5QkmIBtFHrtBZTxaO4sHx1wTQrlbL4/s1600/Acetoacetic+Ester+Synthesis-Organic+reaction.jpg" title="Acyloin Condensation-Organic reaction" /></a></div><a name="more"></a><br /><div class="separator" style="clear: both; text-align: left;"></div>The acyloin condensation usually involves the reductive dimerization of a carboxylic ester, although acid chlorides and the anhydrides have been used. The reducing agent is in an alkali metal and the product is an ene-diolate. Two gram-atoms of metal are required for each mole of ester with the concomitant formation of a mole of akoxide and one-half mole of the ene-diolate. Oxidation of acyloins to diketoes can be accomplished by a variety of reagents. Acyloins can be reduced to ketones by various modifications of the Clemmenson technique. Under mild conditions the ketone will dominate. This chapter presents a complete picture of both the linear and cyclic acyloin condensation with particular emphasis on developments since 1960. The discussion is closely limited to the acyloin condensation and its modifications<br /><h3><span style="color: red; font-size: large;">Acyloin Condensation</span></h3>Acyloin condensation is a reductive coupling of two carboxylic esters using metallic sodium to yield an α-hydroxyketone, also known as an acyloin<span style="color: blue;"><br /></span><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgc1gBiAyc6_ufwcd-Nn2emF-MEEjOWAsky7P9wFOLAiOO8W6l5tBguRgYPqlDCdDv647G23rqz8D43llRd1HwEt0EHYhfwDeRIL2da_05w817lmgONALOjx1d8UvhfIX-hoW3FZXv3ZV8/s1600/Acyloin+Condensation-Organic+reaction.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Acyloin Condensation-Organic reaction" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgc1gBiAyc6_ufwcd-Nn2emF-MEEjOWAsky7P9wFOLAiOO8W6l5tBguRgYPqlDCdDv647G23rqz8D43llRd1HwEt0EHYhfwDeRIL2da_05w817lmgONALOjx1d8UvhfIX-hoW3FZXv3ZV8/s1600/Acyloin+Condensation-Organic+reaction.jpg" title="Acyloin Condensation-Organic reaction" /></a></div><div class="separator" style="clear: both; text-align: left;">The bimolecular reductive coupling of carboxylic esters by reaction with metallic sodium in an inert solvent under reflux gives an α-hydroxyketone, which is known as an acyloin. This reaction is favoured when R is an alkyl. With longer alkyl chains, higher boiling solvents can be used. The intramolecular version of this reaction has been used extensively to close rings of different sizes, e.g. paracyclophanes or catenanes.</div><div class="separator" style="clear: both; text-align: left;"><br /></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgV_pg_EOBLY-GkbmzCWWDH9TQ7uPmDpdhstLBat_lL0LGM3AJ3_s0QrbqJTeWlKK0-w7N_OT0a2DFdTGGr2dtp3zBq8gY5C74bg4qfsWeK5FB_4GiS4phsS_RNojYAHOOZfkF2EmH4q9A/s1600/Acyloin+Condensation-Organic+reaction1.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Acyloin Condensation-Organic reaction" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgV_pg_EOBLY-GkbmzCWWDH9TQ7uPmDpdhstLBat_lL0LGM3AJ3_s0QrbqJTeWlKK0-w7N_OT0a2DFdTGGr2dtp3zBq8gY5C74bg4qfsWeK5FB_4GiS4phsS_RNojYAHOOZfkF2EmH4q9A/s1600/Acyloin+Condensation-Organic+reaction1.jpg" title="Acyloin Condensation-Organic reaction" /></a></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both;">The reaction is carried out in the presence of a proton donor, such as alcohol, simple reduction of the ester to the alcohol takes place (Bouveault-Blanc Reduction).</div><div class="separator" style="clear: both;">The Benzoin Condensation produces similar products, although with aromatic substituents and under different conditions.</div><div class="separator" style="clear: both;">When the acyloin condensation is carried out in the presence of chlorotrimethylsilane, the enediolate intermediate is trapped as the bis-silyl derivative. This can be isolated and subsequently is hydrolysed under acidic condition to the acyloin, which gives a better overall yield.</div><h3 style="clear: both;"><span style="color: blue; font-size: large;">Mechanism of Acyloin Condensation</span></h3><div class="separator" style="clear: both;"><b>The mechanism consists of four steps:</b></div><div class="separator" style="clear: both;">(1) Oxidative ionization of two sodium atoms on the double bond of two ester molecules.</div><div class="separator" style="clear: both;">(2) Free radical coupling between two molecules of the homolytic ester derivative (A Wurtz type coupling). Alkoxy-eliminations in both sides occur, producing a 1,2-diketone.</div><div class="separator" style="clear: both;">(3) Oxidative ionization of two sodium atoms on both diketone double bonds. The sodium enodiolate is formed.</div><div class="separator" style="clear: both;">(4) Neutralization with water to form the enodiol, which tautomerizes to acyloin</div><div class="separator" style="clear: both;"><br /></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj_qSlWnJhMegr_Ac45TgW3LMoSz5Rao8rQOyVqie4Qt5ZXb2HA4wKjXVlZ7RI5VZIo7gGpXemwGEeERBd3fgkDBtarvz5yZI-M06QN39gaSnyEAptDhcVZ00JTNr-JPsL5p1gonv2YTAQ/s1600/Acyloin+Condensation-Organic+reaction3.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Acyloin Condensation-Organic reaction" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj_qSlWnJhMegr_Ac45TgW3LMoSz5Rao8rQOyVqie4Qt5ZXb2HA4wKjXVlZ7RI5VZIo7gGpXemwGEeERBd3fgkDBtarvz5yZI-M06QN39gaSnyEAptDhcVZ00JTNr-JPsL5p1gonv2YTAQ/s1600/Acyloin+Condensation-Organic+reaction3.jpg" title="Acyloin Condensation-Organic reaction" /></a></div><div class="separator" style="clear: both;"><br /></div><h3 style="clear: both;"><span style="color: red; font-size: large;">Rühlmann-method</span></h3><div class="separator" style="clear: both;">The method according to Rühlmann employs trimethylchlorosilane as a trapping reagent; by this, competing reactions are efficiently subdued. Generally, yields increase considerably. The hydrolytic cleavage of the silylether gives the acyloin. To achieve a mild cleavage methanol can be used in several cases.</div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhEhNLqECW2X9yqUwDLsa1duvKEXBjpQ6rLoTbFD9Sb-41zGUrnm8i5U7Q9JVxHBBTMgTg0PDmvApShFZ_jhmPcQwjSem5DqUnOe-pCbSCHk39IQoo8lE35aw6y82NOX9dDyvLXX-JCBBk/s1600/Acyloin+Condensation-Organic+reaction4.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Acyloin Condensation-Organic reaction" border="0" height="101" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhEhNLqECW2X9yqUwDLsa1duvKEXBjpQ6rLoTbFD9Sb-41zGUrnm8i5U7Q9JVxHBBTMgTg0PDmvApShFZ_jhmPcQwjSem5DqUnOe-pCbSCHk39IQoo8lE35aw6y82NOX9dDyvLXX-JCBBk/s1600/Acyloin+Condensation-Organic+reaction4.jpg" title="Acyloin Condensation-Organic reaction" width="640" /></a></div><div class="separator" style="clear: both;"><br /></div><div class="separator" style="clear: both;">Usually toluene, dioxane, tetrahydrofuran or acyclic dialkylethers are employed as solvents. Advantageously also N-methyl-morpholine has been used. It allowed in some cases a successful reaction, in which otherwise the reaction failed in less polar media.</div><h3 style="clear: both;"><span style="color: blue; font-size: large;">Related Reactions</span></h3><div class="separator" style="clear: both;">Bouveault-Blanc Reduction</div><div class="separator" style="clear: both;">Synthesis of Acyloins</div><div class="separator" style="clear: both;"><br /></div><h3><span style="color: red; font-size: large;">Books related to Acyloin Condensation</span></h3>1.<a href="http://www.amazon.com/gp/product/0470462590/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0470462590&linkCode=as2&tag=chemistrandcr-20&linkId=AXABURRWP73O644M" target="_blank">March's Advanced Organic Chemistry: Reactions, Mechanisms, and Structure</a><img alt="" border="0" height="1" src="http://ir-na.amazon-adsystem.com/e/ir?t=chemistrandcr-20&l=as2&o=1&a=0470462590" style="border: none !important; margin: 0px !important;" width="1" />Hardcover – April 22, 2013 by Michael B. Smith<br /><div class="separator" style="clear: both; text-align: left;"><a href="http://www.amazon.com/gp/product/0470462590/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0470462590&linkCode=as2&tag=chemistrandcr-20&linkId=AXABURRWP73O644M" target="_blank"><img alt=" March's Advanced Organic chemistry" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgg6XFnIcvpFvE97IXLFXXb4oYsLJhzq6_vZAK7ufYHkaDS61QPYjrqOhGQHzEJiC1VEKuaODvunfD9HdryvyCktyuJMTxktUWh6lPZB3WLCAUZ8zQMzaPImI1tb6A_WpsWh_JPBhR8vds/s1600/March's%2BAdvanced%2BOrganic%2BChemistry%2BReactions%2C%2BMechanisms%2C%2Band%2BStructur.jpg" title=" March's Advanced Organic chemistry" /></a><a href="http://www.amazon.com/gp/product/0470462590/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0470462590&linkCode=as2&tag=chemistrandcr-20&linkId=AXABURRWP73O644M" target="_blank"><img alt=" Buy Books" border="0" height="100" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjllXtWmsMU-yXyda8OmdUo5_eBRII02eeAFxjEwX0XRnHPrYB9AoKKLsKVCYQVsbFzcN1NhfcMFIZXVR5doawphFEwpFRdFLqPgDyQbex88sLX1lWtFHjQiI2VqI5dtrprisdcktJQX_A/s1600/Buy-Now-button.jpg" title="Acyloin Condensation-Organic reaction" width="200" /></a></div><div class="separator" style="clear: both; text-align: left;"><br /></div><div class="separator" style="clear: both;">The new, revised and updated 7th edition of March’s Advanced Organic Chemistry clearly explains the theories and examples of organic chemistry, providing the most comprehensive resource about organic chemistry available.</div><div class="separator" style="clear: both;"><br /></div><div class="separator" style="clear: both;">2.<a href="http://www.amazon.com/gp/offer-listing/0080966306/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0080966306&linkCode=am2&tag=chemistrandcr-20&linkId=DUX2JUSQGXZ3YG3Y" target="_blank">Organic Syntheses Based on Name Reactions, Third Edition: a practical guide to 750 transformations</a><img alt="" border="0" height="1" src="http://ir-na.amazon-adsystem.com/e/ir?t=chemistrandcr-20&l=as2&o=1&a=0080966306" style="border: none !important; margin: 0px !important;" width="1" /></div><div class="separator" style="clear: both; text-align: left;"><a href="http://www.amazon.com/gp/offer-listing/0080966306/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0080966306&linkCode=am2&tag=chemistrandcr-20&linkId=DUX2JUSQGXZ3YG3Y" target="_blank"><img alt="Organic Syntheses Based on Name Reactions, Third Edition: a practical guide to 750 transformations" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjwnJrouY6it4d5hzTpbPHvRD4XvDhhAPwdWsVt9D2Zxj2GZ1pBGOqE-i57XdjvL2DW1lMBuOLKa6LfZj6_58_DXiMWsUgur3G8eNA4aVdG6ifUsr84G4fpPYKhUSps1HOXoG2dR38ksjY/s1600/Organic+Syntheses+Based+on+Name+Reactions,+Third+Edition+a+practical+guide+to+750+transformations.jpg" title="Organic Syntheses Based on Name Reactions, Third Edition: a practical guide to 750 transformations" /></a><a href="http://www.amazon.com/gp/offer-listing/0080966306/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0080966306&linkCode=am2&tag=chemistrandcr-20&linkId=DUX2JUSQGXZ3YG3Y" target="_blank"><img alt="Acyloin Condensation-Organic reaction" border="0" height="100" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjllXtWmsMU-yXyda8OmdUo5_eBRII02eeAFxjEwX0XRnHPrYB9AoKKLsKVCYQVsbFzcN1NhfcMFIZXVR5doawphFEwpFRdFLqPgDyQbex88sLX1lWtFHjQiI2VqI5dtrprisdcktJQX_A/s1600/Buy-Now-button.jpg" title="Acyloin Condensation-Organic reaction" width="200" /></a></div><div class="separator" style="clear: both; text-align: left;"><br /></div><div class="separator" style="clear: both; text-align: left;">Organic Syntheses Based on Named Reactions is an indispensable reference companion for chemistry students and researchers. Building on Hassner & Stumer's highly regarded 2e, this new work reviews 750 reactions, with over 100 new stereoselective and regioselective reactions. Each A-Z entry provides a carefully condensed summary of valuable information that a chemist needs to understand and utilize these fundamental reactions in their work, including brief practical details. The book is illustrated with real synthetic examples from the literature and about 3,400 references to the primary literature to aid further reading. Extensive indexes (name, reagent, reaction) and a very useful functional group transformation index help the reader fully navigate this extensive collection of important reactions. With its comprehensive coverage, superb organization and quality of presentation, this long-awaited new edition belongs on the shelf of every organic chemist.</div><div class="separator" style="clear: both;"><br /></div><div class="separator" style="clear: both;">3.<a href="http://www.amazon.com/gp/product/008043259X/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=008043259X&linkCode=as2&tag=chemistrandcr-20&linkId=R54CGTTKYCO53DQV" target="_blank">Organic Syntheses Based on Name Reactions, Volume 22, Second Edition (Tetrahedron Organic Chemistry)</a><img alt="" border="0" height="1" src="http://ir-na.amazon-adsystem.com/e/ir?t=chemistrandcr-20&l=am2&o=1&a=008043259X" style="border: none !important; margin: 0px !important;" width="1" /></div><div class="separator" style="clear: both; text-align: left;"><a href="http://www.amazon.com/gp/product/008043259X/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=008043259X&linkCode=as2&tag=chemistrandcr-20&linkId=R54CGTTKYCO53DQV" target="_blank"><img alt="Organic Syntheses Based on Name Reactions, Volume 22, Second Edition (Tetrahedron Organic Chemistry)" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh9y3yT-54Qaqg63KYuYyv-LZq8ozRSB_H2M1NS_ICTWCDgYmPN2cZcGKHvg2fNRCUniz-1W7Wkm73Xg2nAfv5cMif6OLPu7r7NFLljb_lIqtFjw4PImIfw4p28WYMEpo-xApjj7HOLybM/s1600/Organic+Syntheses+Based+on+Name+Reactions,+Volume+22,+Second+Edition+(Tetrahedron%2BOrganic%2BChemistry)1.jpg" title="Organic Syntheses Based on Name Reactions, Volume 22, Second Edition (Tetrahedron Organic Chemistry)" /></a><a href="http://www.amazon.com/gp/product/008043259X/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=008043259X&linkCode=as2&tag=chemistrandcr-20&linkId=R54CGTTKYCO53DQV" target="_blank"><img alt="Acyloin Condensation-Organic reaction" border="0" height="100" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjllXtWmsMU-yXyda8OmdUo5_eBRII02eeAFxjEwX0XRnHPrYB9AoKKLsKVCYQVsbFzcN1NhfcMFIZXVR5doawphFEwpFRdFLqPgDyQbex88sLX1lWtFHjQiI2VqI5dtrprisdcktJQX_A/s1600/Buy-Now-button.jpg" title="Acyloin Condensation-Organic reaction" width="200" /></a></div><div class="separator" style="clear: both; text-align: left;"><br /></div><div class="separator" style="clear: both; text-align: left;">Since the publication of "Organic Syntheses Based on Name Reactions and Unnamed Reactions"(Volume 11 in the Tetrahedron Organic Chemistry series), there has been a proliferation of discoveries of name reactions in the field of organic chemistry. Hence, this, the second, revised, edition of the text has focused on the ongoing development in this area of research. The revised title reflects the notion whereby many new reagents and reactions are now being referred to by their names. The inclusion of over 155 new stereoselective and regioselective reagents or reactions including asymmetric syntheses, brings the total to over 540. Features that should be valuable to the reader include over 3000 references, a names index, reagent index, reaction index and a functional group transformation index. The latter of these indexes will allow the reader to search for conversions of one functional group to another and has proved a much utilized tool for the synthetic chemist, searching for pathways to perform synthetic procedures.</div><div class="separator" style="clear: both;"><b style="color: blue; font-size: x-large;">Sample reactions</b></div><div class="separator" style="clear: both;"><b>1.</b><span style="color: #20124d;"><b>This reaction is from the synthesis of Corannulene by Richard G. Lawton</b></span><a href="http://www.synarchive.com/syn/226" rel="" target="_blank"><span style="color: #990000;">(Read more)</span></a></div><div class="separator" style="clear: both;"><span style="color: red;"><br /></span></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj4o5EX-4VlGEZAt_iFWfwZ3OZ2vyH_rj5o5xbEeKLPLiadiTSLxuSoGarJlHnnrpfMemmdS6mo8pued5ufT3hNAxRuJi1nzGyeGTEgaO6YI87zvEubBYIXIvQAAJ39X3GCLXJur-ImgvY/s1600/Acyloin+Condensation-Organic+reaction.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Acyloin Condensation-Organic reaction" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj4o5EX-4VlGEZAt_iFWfwZ3OZ2vyH_rj5o5xbEeKLPLiadiTSLxuSoGarJlHnnrpfMemmdS6mo8pued5ufT3hNAxRuJi1nzGyeGTEgaO6YI87zvEubBYIXIvQAAJ39X3GCLXJur-ImgvY/s1600/Acyloin+Condensation-Organic+reaction.jpg" title="Acyloin Condensation-Organic reaction" /></a></div><div class="separator" style="clear: both; text-align: left;">2<b>.<span style="color: #20124d;">Acyloin Condensation</span></b></div><div class="separator" style="clear: both; text-align: left;"><br /></div><div class="separator" style="clear: both; text-align: left;">Similar to ester dimerisation, used traditionally to make large rings.</div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjoGXCR90r1NwHISOjW-QW7Rh_nB_WPMRobgEitp51erLfcChpcMJT1EIGAy4LLCI6I0GHAgEPyoB5b3mWj7xbEHAVkYtkr7SJuepnw1URVSlxTWFIOY4IVAjp_kCKktuqdRAKuH96ClqA/s1600/Acyloin+Condensation.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Acyloin Condensation" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjoGXCR90r1NwHISOjW-QW7Rh_nB_WPMRobgEitp51erLfcChpcMJT1EIGAy4LLCI6I0GHAgEPyoB5b3mWj7xbEHAVkYtkr7SJuepnw1URVSlxTWFIOY4IVAjp_kCKktuqdRAKuH96ClqA/s1600/Acyloin+Condensation.jpg" title="Acyloin Condensation" /></a></div><div class="separator" style="clear: both;"><span style="color: blue;"><br /></span></div><div>Now improved by addition of Me3SiCl which traps the intermediate dianion.</div><div><br /></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjh0VCXfLgc729Q-EO96iGNJv4EhB6OxMj-EtLJpok0TEdnFkZtKVNMVA9iY6Mmdj3xsmlN-9XrWoahb53dB3l1ecNRMwVRXI32oT7SPTEViZU1DzdM937W3fKfTMhDLHO-BBTe2cDeY7A/s1600/Acyloin+Condensation1.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Acyloin Condensation-Organic reaction" border="0" height="78" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjh0VCXfLgc729Q-EO96iGNJv4EhB6OxMj-EtLJpok0TEdnFkZtKVNMVA9iY6Mmdj3xsmlN-9XrWoahb53dB3l1ecNRMwVRXI32oT7SPTEViZU1DzdM937W3fKfTMhDLHO-BBTe2cDeY7A/s1600/Acyloin+Condensation1.jpg" title="Acyloin Condensation-Organic reaction" width="640" /></a></div><div><br /></div><blockquote class="tr_bq"><a href="http://www.uea.ac.uk/~c286/notes/retrosynthesis.htm" target="_blank">http://www.uea.ac.uk/~c286/notes/retrosynthesis.htm</a></blockquote>3.<b><span style="color: #20124d;">Acyloin Condensation examples </span><span style="color: red;">(<a href="http://p.pw/badHdQ" rel="nofollow" target="_blank">More</a>)</span></b><br /><b><span style="color: #20124d;"><br /></span></b>Esters undergo a dimerization reduction reaction that is called an acyloin condensation. This name comes from the common name of the simplest reaction product, acyloin, which is an α-hydroxy<br />ketone. The initial product of the reaction is the disodium salt of an enediol. To form the acyloin product, the disodium salt hydrolyzes in aqueous acid.<br /><br /><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgmqv5EGjuDzTdrH681qDOzM7-es0xpRnjwEUl32I4CvmPJtO4lcwWXlHNCnqVLxzbh0VQr3Fi6EQEXulR5Z9PpYv9D7ThTnIp5yC-9WMA33ArXvbrirJk4-4wZVzlEM9eUPCVHF_0_wbY/s1600/Acyloin+Condensation-Organic+reaction1.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Acyloin Condensation-Organic reaction" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgmqv5EGjuDzTdrH681qDOzM7-es0xpRnjwEUl32I4CvmPJtO4lcwWXlHNCnqVLxzbh0VQr3Fi6EQEXulR5Z9PpYv9D7ThTnIp5yC-9WMA33ArXvbrirJk4-4wZVzlEM9eUPCVHF_0_wbY/s1600/Acyloin+Condensation-Organic+reaction1.jpg" title="Acyloin Condensation-Organic reaction" /></a></div><div class="separator" style="clear: both; text-align: left;"><br /></div><div class="separator" style="clear: both;"><b>The acyloin condensation</b> is one of the best methods to use when synthesizing medium to large sized rings. The synthesis begins with the metal and solvent. Then the diester substrate is added very</div><div class="separator" style="clear: both;">slowly. This procedure allows the two ends of the substrate to find each other in an intramolecular reaction, while it suppresses any intermolecular reactions.</div><div class="separator" style="clear: both;"><br /></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjWYJW7KwrngYAgUhDFmVzme_L0_OCHZLaJ50xKsd6qnLLYEnxLPCeixFE53fbU2NggxsViDj1OdGxYmMSwuXSU3l4KgCP_ftka9GoDjh0BJayTc-Uu_YzNAcWyvNnu9DufsEFzlK3YOoQ/s1600/Acyloin+Condensation-Organic+reaction.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Acyloin Condensation-Organic reaction" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjWYJW7KwrngYAgUhDFmVzme_L0_OCHZLaJ50xKsd6qnLLYEnxLPCeixFE53fbU2NggxsViDj1OdGxYmMSwuXSU3l4KgCP_ftka9GoDjh0BJayTc-Uu_YzNAcWyvNnu9DufsEFzlK3YOoQ/s1600/Acyloin+Condensation-Organic+reaction.jpg" title="Acyloin Condensation-Organic reaction" /></a></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: left;">4.<b>Preparation of cyclic acyloins</b></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhRpHPpc68gK0zAxZRxKiRn54lVWabMwR_XoLK6mbGpiWUvATA5xjHc7md_Jw1Ey_iM0pkHAULSY_6W7Ao0iw5thU3-6Ty2i1ZQqPffRkF-GBMEF0SVFcJdeEfL2goIomC6iDYqXolUY_c/s1600/Acyloin+Condensation-Organic+reaction.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Preparation of cyclic acyloins" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhRpHPpc68gK0zAxZRxKiRn54lVWabMwR_XoLK6mbGpiWUvATA5xjHc7md_Jw1Ey_iM0pkHAULSY_6W7Ao0iw5thU3-6Ty2i1ZQqPffRkF-GBMEF0SVFcJdeEfL2goIomC6iDYqXolUY_c/s1600/Acyloin+Condensation-Organic+reaction.jpg" title="Preparation of cyclic acyloins" /></a></div><div class="separator" style="clear: both; text-align: left;"><br /></div><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both;"><br /></div><br /><span style="color: red; font-size: large;">References</span><br /><ol><li>Bouveault, L., and R. Loquin (1905). "Action du sodium sur les éthers des acides monobasiques à fonction simple de la série grasse". Compt. Rend. 140: 1593–1595.</li><li>Finley, K. T. (1964). "The Acyloin Condensation as a Cyclization Method". Chemical Reviews 64 (5): 573–589. doi:10.1021/cr60231a004.</li><li>Bloomfield, J. J.; Owsley, D. C.; Nelke, J. M. Org. React. 1976, 23.Acyloin condensation</li><li>Rühlmann K. (1971). "Die Umsetzung von Carbonsäureestern mit Natrium in Gegenwart von Trimethylchlorsilan" [Reaction of carboxylic acid esters with sodium in the presence of trimethylchlorosilane Synthesis 1971</li><li><a href="http://p.pw/badHbZ" rel="nofollow" target="_blank">Acyloin Ester Condensation(File PDF)</a></li><li><a href="http://p.pw/badHcn" rel="nofollow" target="_blank">Chemistry 144 Organic Synthesis M. E. Jung</a></li></ol><div><h4><span style="color: red; font-size: large;">APPLICATION</span></h4><div><ol><li><b><span style="color: blue;">Preparation of cyclic acyloins </span></b>– This condensation has been used for preparation cyclic acyloins. Long chain dicarboxylic esters have been converted to large ring compounds without the use of dilution technique. It is used best for closing rings of ten members or more.</li><li><b><span style="color: blue;">Preparation of CATENANE </span></b>– CATENANE is a very interesting & unique compound with interlocking rings. It is formed when acyloin condensation was employed for ring closure with esters of 34-carbon dicarboxylic acids.</li></ol></div></div>

Acyloin Condensation-Organic reaction

Acyloin Condensation-Name reaction The acyloin condensation usually involves the reductive dimerization of a carboxylic ester, although acid...

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