What is Claisen Schmidt reaction?
The Claisen-Schmidt condensation reaction is an organic reaction in which a ketone or an aldehyde holding an α-hydrogen reacts with an aromatic carbonyl compound which does not have any α-hydrogens. This reaction is named after the chemists J.G. Schmidt and Rainer Ludwig Claisen.
What is the use of Claisen condensation?
The Claisen condensation of ethyl acetate yields ethyl acetoacetate. This readily available compound and other β-keto esters formed by Claisen condensations are used as intermediates in the synthesis of alkyl derivatives of ketones.
What is difference between aldol and Claisen condensation?
The key difference between aldol condensation and Claisen condensation is that aldol condensation describes the addition of enolates to aldehydes or ketones, whereas Claisen condensation describes the addition of enolates to esters. Claisen condensation progresses with an aldol condensation as a part of it.
Which intermediate is involved in Claisen condensation?
In the ‘main’ part of the Claisen condensation mechanism, the α-carbon of a second acetyl CoA is deprotonated (step 1), forming a nucleophilic enolate. The enolate carbon attacks the electrophilic thioester carbon, forming a tetrahedral intermediate (step 2) which collapses to expel the cysteine thiol (step 3).
What is the major product of Claisen condensation?
The product of a Claisen condensation is a beta-keto ester, which is a significantly stronger acid (pKa = 11) than either alcohols (pKa = 16-17) or esters (pKa = 25).
What reaction type is a Claisen reaction?
The Claisen condensation is a carbon–carbon bond forming reaction that occurs between two esters or one ester and another carbonyl compound in the presence of a strong base, resulting in a β-keto ester or a β-diketone.
Is Claisen condensation in JEE mains?
Although Claisen Condensation and Pinacol Rearrangement do not strictly fall under NCERT syllabus hence a question from that topic ought not be asked in JEE Mains, but I think it is a very important reaction for JEE Advanced and it would be unwise to leave them completely.
What is the product of a Claisen condensation?
What intermediate is formed in Claisen condensation?
Can Claisen condensations be performed with catalytic base?
Although many Claisen condensations are carried out with a full equivalent of the alkoxide base, an effective alternative procedure, used in reaction #5, uses sodium hydride (NaH) together with a catalytic amount of alcohol.
Which Claisen condensations are catalyzed by Thiolase enzymes?
acetyl-CoA
The biosynthetic thiolase catalyzes a Claisen condensation reaction between acetyl-CoA and the enzyme acetylated at Cys89.