Stereoselective α-glycosylation with 3-O-acetylated D-gluco donors
Stereoselective α-glycosylation with 3-O-acetylated D-gluco donors
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DOI：
10.1055/s-2006-939037
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发表时间：
2006-04-04
期刊：
影响因子：
2
通讯作者：
Nifantiev, N
中科院分区：
文献类型：
--
作者：
Ustyuzhanina, N;Komarova, B;Nifantiev, N
研究了3-O-乙酰基对2-O-苄基D-糖基供体的α-糖基化立体选择性的影响。结果表明，3-O-乙酰化供体主要或排他地给出α-异构体，而与相应的全O-苯基化供体的糖基化提供了类似数量的α-异构体和β-异构体的混合物。第一种情况下较高的α-立体选择性是由于3-O-乙酰基的远程锚定辅助作用，理论计算证实了这一点。
The effect of a 3-O-acetyl group on the stereoselectivity of a-glycosylation with 2-O-benzylated D-gluco glycosyl donors was studied. It was shown that 3-O-acetylated donors gave alpha-anomers predominantly or exclusively, whereas glycosylation with the corresponding per-O-benzylated donors afforded Mixtures of comparable amounts of alpha- and beta-anomers. The higher alpha-stereoselectivity in the first case was accounted for by the remote anchimeric assistance of the 3-O-acetyl group, which was confirmed by theoretical calculations.