摘要:
Epoxidation of the allylic alcohols 10 and 11 using the VO(acac)(2)/t-BuOOH system followed by an intramolecular 5-exo cyclization of the resulting 8-epoxycarbamates 12, 13, 18, and 19 has been shown to provide a general and efficient solution for the asymmetric synthesis of polyhydroxy pyrrolidines. The requisite vicinal amino alcohol functionality was enantio-/regio-selectively installed by the Os-catalyzed asymmetric aminohydroxylation reaction of the designed achiral olefin 6. (C) 2004 Elsevier Ltd. All rights reserved.