First enantiospecific synthesis of marine sesquiterpene quinol akaol A

Abstract

The first enantiospecific synthesis of akaol A, a marine sesquiterpene quinol, has been achieved. Key steps of the synthetic sequence are the oxidative degradation of (−)-sclareol to a dinorlabdane ketoester, mediated by the ozone–lead(IV) acetate system, the diastereoselective α-methylation of a ketoaldehyde, followed by an intramolecular aldol condensation and the further Diels–Alder cycloaddition of a dienol ether.