The preparation of the crystalline amide 2 is reported. Conjugate addition to 2 proceeded with the expected high diastereocontrol to give 3. This set the stage for subsequent intramolecular alkylidene C-H insertion to give, after ozonolysis and aldol condensation, (-)-mesembrine 1. Amide 2 should be a useful chiron for the enantioselective construction of cyclic quaternary centers.
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