Synthesis of three marine natural sesterterpenolides from methyl isoanticopalate. First enantioselective synthesis of luffolide.

Formula Chem. The synthesis of three marine sponge metabolites, luffolide (4), 5, and 6, are described for the first time, establishing the absolute configuration of these compounds. The key intermediate, aldehyde 17, wasobtained from methyl isoanticopalate, 11. The addition of 3-furyllithium to 17 and subsequent photochemical oxidation give the γ-hydroxybutenolide 5 and its epimer at C-16. Sesterterpenolide 6 is obtained by dehydration of 5. From the key aldehyde 17, luffolide (4) was obtained in six steps.