An enantioselective approach to furanoeremophilanes: (+)-9-oxoeuryopsin

摘要

An enantioselective total synthesis of the furanoeremophilane sesquiterpene (+)-9-oxoeuryopsin 1 is reported. The synthesis involves as a key step a copper(II) triflate catalyzed tandem asymmetric conjugate addition of AlMe _3 to 2-methyl-2-cyclohexen-1-one with the Feringa (S,R,R)-phosphoramidite binaphthol ligand, followed by aldol condensation of the resulting aluminum enolate with 4-methyl-3-furaldehyde 4. This tandem transformation has not been previously reported with a 2-substituted-2- cyclohexen-1-one. Conventional functional group manipulations completed the synthesis.