Enantioselective construction of cyclic quaternary centers: (-)-mesembrine.
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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Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA. Taberdf@udel.edu
Neubert
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D000470:Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D018360:Crystallography, X-Ray; D006868:Hydrolysis; D007202:Indicators and Reagents; D026121:Indole Alkaloids; D008968:Molecular Conformation; D010126:Ozone; D010946:Plants, Medicinal / Q000737:chemistry*; D013237:Stereoisomerism
D000470:Alkaloids; D007202:Indicators and Reagents; D026121:Indole Alkaloids; D010126:Ozone; C011300:mesembrine