Catalytic Asymmetric Synthesis of Complex Polypropionates: Lewis Base Catalyzed Aldol Equivalents in the Synthesis of Erythronolide B

Abstract

Powerful aldol reactions: Stereoselective Lewis base catalyzed aldol equivalents expediently provided eight of the ten stereocenters required for the synthesis of erythronolide B. Indeed, all eleven stereocenters present in the erythromycin aglycone have been derived directly or indirectly from catalytic asymmetric equivalents of aldol addition reactions (see scheme).