Synthesis of some N-substituted 4-piperidones

Abstract
A single-stage synthesis of methyl and ethyl N-benzoyl-4-piperidone-3-carboxylates from benzamide and the appropriate alkyl acrylate is reported. The esters have been directly converted into N-benzoyl-4-piperidone. The use of t-butyl esters in the Dieckmann synthesis of N-phenyl-4-piperidone-3-carboxylates leads to an increased yield of N-phenyl-4-piperidone.