Synthesis of (-)-pericosine B, the antipode of the cytotoxic marine natural product.

The stereoselective synthesis of (-)-pericosine B, which is the antipode of the cytotoxic metabolite of the fungus Periconia byssoides OUPS-N133 separated from the sea hare, was accomplished in 9 steps in 12% total yield from (-)-quinic acid, together with the synthesis of its epimer. Every crucial step of this total synthesis, including ring opening of a beta-epoxide and NaBH4 reduction of an unstable beta,gamma-unsaturated enone, proceeded with excellent stereoselectivity.