| 摘要 |
PURPOSE:To obtain a new glycosyl donor simply, in high yield and high selectivity by reacting an acyltetraalkylglycopyranoside with a trimethylsilyl ether of an alcohol in the presence of a catalytic amount of an acidic catalyst. CONSTITUTION:(A) A 1-O-acyl-2,3,4,6-tetra-O-alkyl-D-glycopyranoside is reacted with (B) a trimethylsilyl ether of an alcohol in the presence of a catalytic amount of a Lewis acid or a mixed catalyst of a lewis acid and silver perchlorate or silver trifluoromethanesulfonate in an ether-based solvent to give an alpha-D- glycopyranoside derivative or /9-D-glucopyranoside derivative of respectively formura I or formula II (R; benzyl, p-methoxybenzyl, etc.) (e.g. 1-O- cyclohexyl-2,3,4,6-tetra-O-benzyl-D-glucopyranose). |
