Highly Enantioselective Intramolecular Hetero Diels‐Alder Reactions for the Synthesis of Enantiomerically Pure Tricyclic Lactones

Abstract

An intramolecular cycloaddition with 98% ds can be achieved with the heterodiene 1, R1R2H. The cis-annelated (7aS, 13bR)-tetracycle 2 thus obtained affords the lactone 3 upon cleavage of the chiral auxiliary group.