Total synthesis of (-)-cleistenolide.

The first total synthesis of Cleistenolide, a novel natural product recently isolated from the Annonaceae species Cleistochlamys kirkii Oliver, is described. The synthesis proceeds in six steps and 18% overall yield, starting from an enantiopure C2-symmetric building block and using a Sharpless epoxidation, a selective epoxide opening, and a ring-closing metathesis reaction.