The chemistry of isopropenyl glycopyranosides. Transglycosylations and other reactions
The chemistry of isopropenyl glycopyranosides. Transglycosylations and other reactions
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DOI：
10.1021/jo960190p
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发表时间：
1996-07-26
影响因子：
3.6
通讯作者：
Yang, J
中科院分区：
文献类型：
--
作者：
Chenault, HK;Castro, A;Yang, J
已经合成了各种异头纯的异丙烯基α-和β-吡喃糖苷，并显示出与各种伯和仲碳水化合物醇进行合成上有用的转糖基反应。虽然储存时稳定，但异丙烯基糖苷很容易被各种亲电子试剂激活为糖基供体，包括 N-碘代琥珀酰亚胺/三氟甲磺酸、三甲基甲硅烷基三氟甲磺酸酯和三氟甲磺酸酐。在阻碍糖基阳离子形成的条件下，异丙烯基糖苷的反应性从转糖基化转向通过乙烯基醚双键的亲电加成。
Various anomerically pure isopropenyl alpha- and beta-glycopyranosides have been synthesized and shown to undergo synthetically useful transglycosylation reactions with a variety of primary and secondary carbohydrate alcohols. Although stable when stored, isopropenyl glycosides are readily activated as glycosyl donors by a variety of electrophiles, including N-iodosuccinimide/triflic acid, trimethylsilyl triflate, and triflic anhydride. Under conditions that retard formation of the glycosyl cation, the reactivity of isopropenyl glycosides is diverted away from transglycosylation and toward electrophilic addition across the vinyl ether double bond.