Claisen condensation

Earlier, we examined the aldol reactions as a nucleophilic carbonyl addition in section 20.6, in which the electrophile is the carbonyl carbon of an aldehyde or ketone.  A nucleophilic enolate can also attack the carbonyl carbon of a carboxylic acid derivative in a nucleophilic acyl substitution reaction.This is referred to as a Claisen condensation, after the German chemist Ludwig Claisen (1851-1930).

Basic reaction

Going from reactants to products simply 

 

Example: Claisen Condensation

Claisen condensation mechanism

1) Enolate formation

2) Nucleophilic attack

3) Removal of leaving group