Stereoselective Synthesis of Benzomorphan Derivatives with Perpivaloylated Galactose as the Chiral Auxiliary

Abstract

“Which way, sugar?” The cyclization of benzyl-substituted N-galactosyl didehydropiperidinones leads stereoselectively to regioisomerically annelated and highly substituted benzomorphan derivatives, which are pharmacophorically relevant structural elements (see scheme). The perpivaloylated N-galactosyl auxiliary controls the stereo- as well as the regioselectivity of the reaction.