An intramolecular Diels-Alder approach to the eunicellins: Enantioselective total syntheses of ophirin B and astrogorgin

The enantioselective syntheses of the eunicellins ophirin B and astrogorgin have been completed. Ring-closing metatheses provide efficient access to the oxonene rings, and highly diastereoselective intramolecular Diels-Alder reactions resulted in the formation of the hydrobenzofuran portion of the molecules.