Enantioselective Synthesis ofcis-Decalin Derivatives by the Inverse-Electron-Demand Diels-Alder Reaction of 2-Pyrones

摘要

A novel strategy for the synthesis ofcis-decalins by an ytterbium-catalyzed asymmetric inverse-electron-demand Diels-Alder reaction of 2-pyrones and silyl cyclohexadienol ethers is reported here. A broad range of synthetically importantcis-decalin derivatives with multiple contiguous stereogenic centers and functionalities are obtained in good yields and stereoselectivities. A full set of diastereomeric substitutedcis-decalin motifs are readily accessible by tuning the absolute configurations of substituted silyl cyclohexadienol ethers (RorS) as well as the ligands (RorS). The synthetic potential is showcased by the enantioselective total synthesis of 4-amorphen-11-ol, and further demonstrated by the first total synthesis ofcis-crotonin.