An efficient protocol for the stereoselective synthesis of C-2-methylene-α- and -β-C-glycosides by a Claisen rearrangement of 2-vinyloxymethyl glycal derivatives is reported. A plausible mechanism for the formation of α-selective-C-glycoside was proposed. The methodology was further extended to the high diastereoselective synthesis of C-2-methyl-C-glycosides.
本文报道了通过2-
乙烯氧基甲基
甘油衍
生物的克莱森重排实现C-2-亚甲基-α-和-β-C-糖苷立体选择性合成的有效方案。提出了α-选择性-C-糖苷形成的合理机制。该方法进一步扩展到C-2-甲基-C-糖苷的高立体选择性合成。