Formal total synthesis of (−)-spongidepsin

The formal total synthesis of (−)-spongidepsin is described. Three fragments I, II, and III were first prepared from readily available starting materials and then assembled to the target compound. The key steps involved in the synthesis are asymmetric α-hydroxylation, Enderʹs alkylation, and ring-closing metathesis reactions. An alternative route for the fragment II is also achieved involving Sharpless asymmetric epoxidation and Gilmanʹs alkylation as key reactions.