An Asymmetric Synthesis of Benzylic Quaternary Carbon Centers. A Formal Total Synthesis of (-)-Mesembrine

Article abstract of DOI:10.1016/S0040-4039(00)78256-6

The optically pure sulfone 15, prepared by tandem asymmetric epoxidation and 1,2-rearrangement of the cyclopropylideneethanol 11 as a key step, was converted into the olefinic cyclobutanone 20 which was then transformed into the ketonic lactone 22 via the