Lam Son N, Gervay-Hague Jacquelyn
Department of Chemistry, University of California, Davis, One Shields Ave., Davis, California 95616, USA.
Org Lett. 2003 Oct 30;5(22):4219-22. doi: 10.1021/ol035705v.
[reaction: see text]. The conversion of glycals to 2-deoxy glycosyl acetates followed by reaction with trimethylsilyl iodide affords the corresponding glycosyl iodides, which readily undergo substitution with aryl alkoxy anions to provide 2-deoxy-beta-O-aryl glycosides. Direct displacement of the anomeric iodide alleviates the need to introduce temporary C-2 stereodirecting groups that require subsequent removal. The only observable byproducts from the glycosylations result from elimination of HI giving the starting glycals, which can be recycled through the reaction sequence.
[反应:见正文]。将缩水甘油转化为2-脱氧糖基乙酸酯,然后与三甲基甲硅烷基碘反应,得到相应的糖基碘化物,该糖基碘化物很容易与芳基烷氧基阴离子发生取代反应,生成2-脱氧-β-O-芳基糖苷。端基碘的直接取代消除了引入需要后续去除的临时C-2立体定向基团的必要性。糖基化反应中唯一可观察到的副产物是由HI消除生成起始缩水甘油,其可通过反应序列循环利用。