The claisen condensation reaction Esters, like aldehydes and ketones,are weakly acidic. When an ester with an alpha hydrogen is treated with one equivalent of a base such as sodium ethoxide, a reversible condensation reaction occurs to yield a p-keto ester product. This reaction between two ester components is known as the Claisen condensation reactionOrganic Chemistry Organic Chemistry Xiamen Xiamen University University The Claisen Condensation Reaction „ Esters, like aldehydes and ketones, are weakly acidic. When an ester with an alpha hydrogen is treated with one equivalent of a base such as sodium ethoxide, a reversible condensation reaction occurs to yield a β−keto ester product. This reaction between two ester components is known as the Claisen condensation reaction