Lohman Gregory J S, Seeberger Peter H
Massachusetts Institute of Technology, 77 Massachusetts Avenue 18-292, Cambridge, Massachusetts 02139, USA.
J Org Chem. 2003 Sep 19;68(19):7541-3. doi: 10.1021/jo034386i.
Described is a general method for the conversion of glycals to the corresponding 1,2-cis-isopropylidene-alpha-glycosides. Epoxidation of glycals with dimethyldioxirane followed by ZnCl(2)-catalyzed addition of acetone converted a variety of protected glycals into 1,2-cis-isopropylidene-alpha-glycosides in good yield. The reaction is compatible with a range of protecting groups, including esters, benzyl ethers, and silyl ethers, as well as free hydroxyl groups. This method has been applied to develop a synthesis of protected glucuronic acid 1, a key intermediate in the synthesis of glycosaminoglycans. Compound 1 was produced in seven steps and 32% overall yield.
描述了一种将糖烯转化为相应的1,2-顺式异亚丙基-α-糖苷的通用方法。用二甲基二氧杂环丙烷对糖烯进行环氧化，然后在氯化锌催化下加入丙酮，可将多种保护的糖烯以良好的产率转化为1,2-顺式异亚丙基-α-糖苷。该反应与一系列保护基团兼容，包括酯基、苄基醚和硅烷基醚，以及游离羟基。该方法已被用于开发一种保护型葡萄糖醛酸1的合成方法，葡萄糖醛酸1是糖胺聚糖合成中的关键中间体。化合物1经过七步反应制得，总产率为32%。
