Total Synthesis of (−)-Enigmazole A by the Macrocyclization/Transannular Pyran Cyclization Strategy

Abstract

An 18-step synthesis of (−)-enigmazole A is herein disclosed. The present synthesis is based on a modular assembly of three building blocks of similar complexity, a macrocyclic ring-closing metathesis to forge the 18-membered macrocyclic skeleton, and a desilylative transannular oxa-Michael addition for stereoselective construction of the 2,6-cis-substituted tetrahydropyran ring.