Stereoselective synthesis of the macrocyclic core (C7–C19) of carolacton

Abstract

Carolacton, a secondary metabolite, was isolated from the myxobacterium Sorangium cellulosum. It exhibits excellent antibacterial activity at nanomolar concentrations. We report the synthesis of the macrocyclic core of carolacton, comprising the C7–C19 fragment with five out of the eight stereocentres. The key reactions involved are: Sharpless asymmetric epoxidation, metal chelated epoxide opening, Yamaguchi esterification and ring closing metathesis (RCM). The present study utilizes a simple synthetic strategy, adopting asymmetric and chiron approaches.