The exo-selectivity of the new non-natural chiral auxiliary (+)-(1 R, endo)-2-benzonorbornenol in an asymmetric aza-Diels–Alder reaction

Abstract

The recently reported compound (+)-(1 R, endo)-2-benzonorbornenol ( 2 ) proved to be an efficient chiral auxiliary in the asymmetric aza-Diels–Alder reaction between cyclopentadiene and the N-benzyl imine of its glyoxylate, which afforded a virtually all- exo mixture of cycloaducts with a 1 S:1 R diastereomeric ratio of 63:37.