Enantioselective Total Synthesis of Chondrosterins I and J by Catalytic Asymmetric Intramolecular Aldol Reaction Using Chiral Diamine Catalyst

Abstract

The first enantioselective total synthesis of chondrosterins I and J was accomplished. The synthetic method focuses on an intramolecular aldol reaction through catalytic asymmetric desymmetrization using chiral diamine catalyst. An intensive investigation of this reaction improved the enantiomeric excess up to 92 % ee. In addition, stereoselective reduction of the ketone moiety efficiently converted chondrosterin I to chondrosterin J.