Enantioselective Synthesis of (+)-Auriculatol A

A total synthesis of the grayanane diterpenoid (+)-auriculatol A is reported. The synthesis features a convergent coupling strategy that joins two fragments by a vinylogous Mukaiyama-aldol-type reaction and then constructs the 7-membered ring by a Ni-catalyzed enolate alkenylation. Key findings include the development of a chemoselective Ni-catalyzed intramolecular 1,2-addition to access the bicyclo3.2.1octane fragment and the use of electron-deficient olefin supporting ligands as uniquely effective for the Ni-catalyzed enolate alkenylation.