Ketonic Decarboxylation Catalysed by Weak Bases and Its Application to an Optically Pure Substrate

Ketonic decarboxylation is a very old reaction that transforms two carboxylic acids into a ketone or a dicarboxylic acid into a cyclic ketone, in particular adipic acid into cyclopentanone. Herein it is reported that catalytic amounts of weak bases such as sodium carbonate can carry out this reaction selectively. This is in accordance with a mechanism involving decarboxylation and nucleophilic attack at a second carboxyl group. The reaction can be employed in asymmetric syntheses since the stereogenic centres in the β‐positions retain their stereochemistry. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)