synthesis and rearrangements of the chiral carbinols and are described. With KH-THF. both the carbinola gave optically active rearrangement products; with alkali in methanol, they gave optically inactive rearrangement products. The results are interpreted as favouring a concerted mechanism for the hydride catalysedrearrangements and a non-concerted mechanism for the rearrangementscatalysed by alkali