An efficient synthesis of optically active five- and six-membered cyclic compounds with selectable stereo-controls by a Ti(II)-mediated cyclization of chiral secondary 2,7- and 2,8-enyn-1-ol derivatives

Ti(II)-mediated cyclization of readily accessible optically active secondary 2,7- and 2,8-enyn-1-ol derivatives enables the selective preparation of any one of the four possible stereoisomers of the cyclized product with high optical purity.