Enantioselective Total Synthesis of Marine Natural Products Untenone A and Plakevulin A

An enantioselective total synthesis of untenone A and plakevulin A has been achieved. Construction of a cyclopentene derivative, the key intermediate in this synthesis, was carried out by using a ruthenium-catalyzed ring-closing metathesis reaction of a divinyl compound, prepared from octadecanal in several steps including the Sharpless asymmetric epoxidation to generate a chiral quaternary carbon center.