Synthesis and stereochemistry of the antitumor diterpenoid (+)-zerumin B.

Starting from commercially available (+)-sclareolide, the first synthesis of zerumin B was achieved by a concise, highly efficient pathway featuring stereoselective addition of a new silyloxyfuryltitanium reagent to an aldehyde intermediate and silyloxyfuran oxyfunctionalization as key steps. The synthesis established the relative and absolute configuration of zerumin B along with its identity with a purportedly new diterpenoid isolated from the plant Renealmia alpinia.