A new route to enantiomerically pure 4,4-disubstituted cyclohex-2-en-1-ones: Asymmetric synthesis of (+)-mesembrine

Article abstract of DOI:10.1016/S0957-4166(00)80327-4

Enantiomerically pure β,β-disubstituted vinyl sulfoxides undergo cycloaddition with dichloroketene to give β,β-disubstituted γ-lactones which are transformed into synthetically important 4,4-disubstituted cyclohex-2-enones in optically pure form. The present method is applied to the synthesis of enantiomerically pure (+)-mesembrine.