Enantioselective Construction of Bridged Multicyclic Skeletons:Intermolecular [2+2+2] Cycloaddition/Intramolecular Diels-Alder Reaction Cascade

摘要

The intramolecular Diels-Alder (IMDA) reaction is a powerful strategy for the construction of complex multicyclic skeletons.The construction of the bridged multicyclic skeleton C, from phenol A, has been reported to proceed through oxidative dearomatization to give allyl cyclohexa-dienyl ether B, which then undergoes the IMDA reaction to yield C (Scheme 1). This novel strategy was successfully applied to the synthesis of various complex natural products, but an asymmetric variant has not yet been developed because of the difficulty of the enantioselective dearomatization of phenols.