中文摘要：

在乙腈等5种不同溶剂中,以2,3,4-O-三苄基-6-O-（2-氟苄基）-β-对甲基苯基-D-葡萄糖硫苷作为糖基供体,甲醇作为受体,并以糖基化供体2,3,4,6-O-四苄基-β-对甲基苯基-D-葡萄糖硫苷为对照,研究了在葡萄糖硫苷C-6位引入氟取代基对糖苷键立体选择性的影响。结果表明,引入的2-氟苄基与普通苄基保护基相比,β构型比例都有一定程度的提高,其中当溶剂为乙腈时,β构型比例较在其他溶剂中提升最明显,α/β比值可达到1/4.7。

英文摘要：

Using 2,3,4-tri-O-benzyl-6-O-（2-fluorobenzyl） -β-p-methylphenyl-l-thio-D-glucopyranoside as glycosyl donor, 2,3,4,6-O-tetrabenzyl-p-methylphenyl-l-thio-D-glucopyranoside as reference substance, glycosylation reactions were carried out in acetonitrile and other four different solvents with methanol as acceptor to study the influence of fluorine atoms on the stereoselective of glycosylation. The results showed that glycosyl donor with 2- fluorobezyl as C-6 protecting group selectively affords the 1,2-trans-glycosidic bonds by inducing glycosyl acceptors attacking from the β-face. Notably, the α/β ratio （1/4.7） was improved when using acetonitrile as the glycosylation solvent.