Claisen Condensation: Building Beta-Ketoesters

Claisen condensation is a reaction that builds beta-ketoesters from ester molecules. It uses an alkoxide base and works best with identical esters that have two alpha hydrogens. These alpha hydrogens are important because the base removes one of them to start the reaction.

The first step forms a ...

Recall regular Claisen condensation as a method to obtain β-ketoesters from identical ester molecules containing two α protons in the presence of an alkoxide base.

The reaction begins with the base abstracting the acidic α hydrogen from the ester to produce a nucleophilic enolate ion stabilized by resonance.

The nucleophile attacks...