Total Synthesis of the Z-Isomers of the Proposed and Revised Structures of Aspergillide B via an Iodocyclization and Ring-Closing Metathesis Strategy

Abstract

The synthesis of Z -isomers of both the proposed and revised structures of aspergillide B is described. A divergent route is employed that involves kinetically controlled ring-closing metathesis for the construction of a 14-membered macrocyclic ring, ester formation under Yamaguchi conditions, a Wacker-type oxidative cyclization for creation of the C4 stereogenic center and a previously reported diastereoselective isomerization–iodocyclization strategy for the construction of the 2,6- trans -disubstituted tetrahydropyran subunit.