Regio- and Stereoselectivity in the Reductions of Cyclic Enedione Systems
摘要:
Reductions of cyclic enedione substrates by NaBH4 and by LiAl(O-t-Bu)(3)H very predominantly gave monoreduction products with very high regio- and stereoselectivity. The reductions involved axial delivery of the hydride. The results indicated that electronic factors were dominated by steric considerations in the transition state of the reduction, even though the seemingly more encumbered carbonyl was reduced.
Regio- and Stereoselectivity in the Reductions of Cyclic Enedione Systems
作者:Chunjian Liu、D. Jean Burnell
DOI:10.1021/jo962377m
日期:1997.5.1
Reductions of cyclic enedione substrates by NaBH4 and by LiAl(O-t-Bu)(3)H very predominantly gave monoreduction products with very high regio- and stereoselectivity. The reductions involved axial delivery of the hydride. The results indicated that electronic factors were dominated by steric considerations in the transition state of the reduction, even though the seemingly more encumbered carbonyl was reduced.
Fieser; Seligman, Chemische Berichte, 1935, vol. 68, p. 1747,1749