Characteristics of reduction of 2- alkyn-1-ols by lithium and sodium hydrides in tetrahydrofuran

1. MAlH3(OCH2C≡CR) and MAlH2(OCH2≡ CR)2 complexes disproportionate in a THF solution to MAlH4 and MAlH(OCH2C≡CR)3. 2. Complete reduction of 2-alkyn-1-ols is obtained in a continuous hydride-ligand exchange between MAlH4 and (RC≡CHCH20)Al(OCH2C≡CR)2M. 3. With increase in the solvating power of the solvent, the radius of the cation decreases, and on introduction of electron-donor additives the yield of the γ-substituted allyl alcohols increases. Decrease in the solvating power of the solvent, increase in the radius of the cation, and introduction of electron-acceptor additives leads to an increase in the yield ofβ-substituted allyl alcohols.