论文部分内容阅读
目的立体专一性地合成带有易于选择性地脱除的保护基的二糖半乳糖基(α1→2)葡萄糖苷片段。方法以D-葡萄糖为原料,经过乙酰化、溴代、甲基化、脱乙酰基、苯亚甲基化、选择性苯甲酰化、氯乙酰化、脱氯乙酰基,合成甲基-3,4,6-三-O-苯甲酰基-β-D-葡萄糖苷;该葡萄糖苷受体与供体异丙基-2-O-苯甲酰基-3-O-烯丙基-4,6-O-苯亚甲基-β-D-1-硫代半乳糖苷在催化剂作用下反应,获取α-偶联的二糖产物。结果半乳糖供体与葡萄糖受体在TMSOTf/NIS的催化下偶联,立体专一性地得到了全保护的二糖半乳糖基(α1→2)葡萄糖苷片段甲基-2-O-苯甲酰基-3-O-烯丙基-4,6-O-苯亚甲基-α-D-半乳糖基(1→2)-3,4,6-三-O-苯甲酰基-β-D-葡萄糖苷,产品经NMR、MS确证。结论在半乳糖供体和葡萄糖受体的特定结构的共同影响下,立体专一性地获得了全保护的1,2-顺式的二糖片段。
The purpose of stereospecifically synthesizing disaccharide galactosyl (α1 → 2) glucoside fragments with a protective group that can be selectively and easily removed. Methods D-glucose was used as the starting material to synthesize methyl-3-thioacetate by acetylation, bromination, methylation, deacetylation, benzylidenelation, selective benzoylation, , 4,6-tri-O-benzoyl-β-D-glucoside; the glucoside receptor binds to the donor isopropyl-2-O-benzoyl-3-O-allyl-4, 6-O-benzylidene-β-D-1-thiogalactoside is reacted under the action of a catalyst to obtain the α-coupled disaccharide product. Results The galactose donor and glucose acceptor were coupled under the catalysis of TMSOTf / NIS, and the fully protected disaccharide galactosyl (α1 → 2) glucoside fragment methyl-2-O-benzene Formyl-3-O-allyl-4,6-O-benzylidene-α-D-galactosyl (1 → 2) -D-glucoside, the product confirmed by NMR, MS. CONCLUSIONS The fully protected 1,2-cis disaccharide moiety was obtained stereospecifically under the combined influence of the specific structure of the galactose donor and the glucose acceptor.