Variations of Claisen Condensation
The Claisen condensation is a carbon-carbon bond-forming reaction that involves the formation of a β-keto ester or a β-diketone. There are three main variations of the Claisen condensation: classic Claisen condensation, crossed Claisen condensation, and Dieckmann condensation.
Classic Claisen condensation
It is a self-condensation between two molecules of a compound containing an enolizable ester.
Example reaction: R1COOR2 + R3COOR4 → R1COR3COOR4 + R2O
Crossed Claisen condensation
It involves the enolate of one ester reacting as a nucleophile with a different (ideally non-enolizable) ester or ketone.
Example reaction: R1COOR2 + R3COR4 → R1COR3COOR2 + R4O
Dieckmann condensation
It is an intramolecular variant of the Claisen condensation, where a molecule featuring two ester groups undergoes an intramolecular reaction to form a cyclic β-keto ester.
Example reaction: R1COOR2CH2COOR2 → R1COOCH2COR2 + R2COO
Claisen Condensation
Claisen condensation is an organic reaction that forms a new carbon-carbon bond, producing a β-keto ester. It involves the condensation of two esters or one ester and a carbonyl compound in the presence of a strong base, forming a β-keto ester or a β-diketone. It was discovered by German chemist Ludwig Claisen in 1887. In this article, we will look into What Claisen Condensation is, its mechanism, examples, types, etc.