# 24.5 The Claisen Condensation

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Because esters can contain α hydrogens they can undergo a condensation reaction similar to the aldol reaction called a Claisen Condensation. In a fashion similar to the aldol, one ester acts as a nucleophile while a second ester acts as the electrophile. During the reaction a new carbon-carbon bond is formed. The product is a β-keto ester. A major difference with the aldol reaction is the fact that hydroxide cannot be used as a base because it could possibly react with the ester. Instead, an alkoxide version of the alcohol used to synthesize the ester is used to prevent transesterification side products.

## Claisen Condensation

Basic reaction

Going from reactants to products simply

Example 1: Claisen Condensation

## Claisen Condensation Mechanism

1) Enolate formation

2) Nucleophilic attack

3) Removal of leaving group

## Contributors

This page titled 24.5 The Claisen Condensation is shared under a not declared license and was authored, remixed, and/or curated by Layne Morsch.