A new artificial cyclase for polyprenoids: enantioselective total synthesis of (-)-chromazonarol, (+)-8-epi-puupehedione, and (-)-11'-deoxytaondiol methyl ether.

This paper describes a new artificial cyclase, optically pure 3-o-fluorobenzyloxy-2-hydroxy-2'-(p-methoxybemzyl)-1,1'-binaphthyl.SnCl4, which is effective for the enantioselective cyclization of 2-(polyprenyl)phenol derivatives to afford polycyclic terpenoids bearing a chroman skeleton such as (-)-chromazonarol, (+)-8-epi-puupehedione, a key synthetic intermediate of (+)-wiedendiol, and (-)-11'-deoxytaondiol methyl ether.