The synthesis and rearrangement of the optically active etynyl and vinyl carbinols 3 and 4 are reported. The rearrangements are found to be concerted when carried out with KH-THF and non-concerted with KOH-methanol.
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