A simple access to lactose-derived building blocks required in glycoconjugate synthesis
作者:Luigi Lay、Rainer Windmüller、Stefan Reinhardt、Richard R. Schmidt
DOI:10.1016/s0008-6215(97)00135-3
日期:1997.8
lactose building blocks required in oligosaccharide and glycoconjugate synthesis. Thus, from 5 via per-O-benzoylation, desilylation, trichloroacetimidate formation, glycosylation of the Lemieux spacer, and acid-catalyzed de-O-isopropylidenation methoxycarbonyloctyl (2,6-di-O-benzoyl-beta-D-galactopyranosyl)- (1-->4)-2,3,6-tri-O-benzoyl-beta-D-glucopyranoside (12) was obtained. Regioselective benzoylation
乳糖很容易转化为己基二甲基甲硅烷基(3,4-O-异亚丙基-β-D-吡喃半乳糖基)-(1-4)-β-D-吡喃葡萄糖苷(5); 该化合物可作为中间体,用于生成寡糖和糖缀合物合成所需的部分受O保护的乳糖结构单元。因此,从5开始,通过全-O-苯甲酰化,去甲硅烷基化,三氯乙酰亚氨酸酯的形成,Lemieux间隔基的糖基化和酸催化的脱-O-异亚丙基甲氧基羰基辛基(2,6-二-O-苯甲酰基-β-D-吡喃半乳糖基)-得到(1→4)-2,3,6-三-O-苯甲酰基-β-D-吡喃葡萄糖苷(12)。在各种条件下用苯甲酰氰进行5的区域选择性苯甲酰化,得到3-O-(13),2,3,2'-O-(14),3,2'-O-(16)和2,2'-O -未保护的(17)乳糖苷。16的De-O-异亚丙基化产生了thexyldimethylsilyl(6-O-benzoyl-beta-D-galactopyranosyl)-(1-> 4