AN EFFICIENT METHOD FOR THE OPTICAL RESOLUTION OF 3-HYDROXY-2-SUBSTITUTED-4-ALKYNOATES - A HIGHLY STEREOSELECTIVE TOTAL SYNTHESIS OF (+)-BENGAMIDE-E

A novel. procedure for the optical resolution of 3-hydroxy-2-substituted-4-alkynoates and its application to the stereoselective total synthesis of (+)-bengamide E are described. 3-Hydroxy-2-substituted-4-alkynoates, derived from the aldol reaction of cobalt-complexed propynals with ketene O-silyl O,S-acetals, were easily resolved by the formation of a chiral carbamate followed by cobalt complexation. Chiral 2-(benzyloxy)-3-hydroxy-4-alkynoate derivatives thus obtained were used as starting materials for a highly stereoselective total synthesis of (+)-bengamide E.