Selectivity in the SmI2-induced deoxygenation of thiazolylketoses for formyl C-glycoside synthesis and revised structure of C-ribofuranosides
作者:Alessandro Dondoni、Paolo Formaglio、Alberto Marra、Alessandro Massi
DOI:10.1016/s0040-4020(01)00736-0
日期:2001.9
Deoxygenation of thiazolylketose acetates using SmI2–(CH2OH)2 or TMSOTf–Et3SiH affords thiazolyl C-glycosides with opposite α/β ratios. Examination of the thiazolyl α- and β-C-ribofuranoside pair by NOE experiments reveals that the earlier configuration assigned to one of these isomers has to be revised. Having prepared authentic anomeric α- and β-ribofuranose aldehydes from the corresponding thiazolyl
使用SmI 2-(CH 2 OH)2或TMSOTf-Et 3 SiH对乙酸噻唑基酮糖乙酸进行脱氧,得到具有相反α/β比的噻唑基C-糖苷。通过NOE实验对噻唑基α-和β- C-核呋喃糖苷对的研究表明,必须修改分配给这些异构体之一的早期构型。已经制备正品异头α-和β-D-呋喃核糖醛从相应的噻唑基C ^由噻唑环的裂解-glycosides,各醛转化到(1→6) - c ^通过Wittig烯化-disaccharides与半乳糖6-正膦。