Two different approaches to the enantioselective syntheses of (+)-sedamine and (-)-allosedamine
are described, both using the Sharpless asymmetric epoxidation as the key step. Regioselective
reduction of epoxides, chemoselective oxidation of alcohols, ring-closing metathesis,
and nucleophilic displacements were the other key steps employed.
alkaloids - asymmetric synthesis - regioselective reduction - ring-closing metathesis
