Enantioselective synthesis of (3R,6S,7R,18R,19S)-, (3R,6S,7R,18R,19R)-, and (3R,6S,7R,18S,19R)-Quassiols A. A comment on the stereochemistry of natural quassiol A
Total synthesis of antimalarial diterpenoid (+)-kalihinol A, isolated frommarinespongeAcanthella sp., is achieved. This total synthesis involves regioselective alkylation of an epoxide, construction of a tetrahydropyran ring by iodo-etherification, construction of a cis-decalin ring by intramolecular Diels-Alder reaction, isomerization of cis-decalin to trans-decalin, and subsequent functionalization
Totalsynthesis of marinediterpenoid kalihinene X was achieved. This totalsynthesis involves regioselective coupling reaction of carbanion of alkyl sulfone with epoxyalcohol and construction of cis-decalin ring by intramolecular Diels–Alder reaction. The absolute configuration of kalihinene X could be determined by this totalsynthesis.