A strategy toward the synthesis of C-oxidized cembrenolides.

An efficient strategy for the construction of C-oxidized cembrenolides is reported. Central to this strategy is the installation of the C hydroxyl group prior to cembrane macrocyclization (via formation of the C-C bond), allowing access to both C alcohol epimers. The orientation of the C alcohol was found to influence the cyclization mode of the cembranolide scaffold upon furan oxidation, leading to motifs reminiscent to bipinnatolide F, bielschowskysin, and verrillin.