Synthesis of Standardized Building Blocks as a β-D-Mannosyl Donors with a Temporary Protection to be 3,6-Di-<i>O</i>-glycosyl Acceptors, for Constructing the Inner Core of Glycoproteins and Artificial Antigens
作者:El Sayed H. El Ashry、Conrad Schuerch
DOI:10.1246/bcsj.59.1581
日期:1986.5
The synthesis was started by methyl 2,3-O-isopropylidene-α-D-mannopyranoside, which upon benzylation, deisopropylidenation, and selective acetolysis of the 6-O-benzyl group afforded the corresponding tetraacetate, which could be converted to 3,6-di-O-allyl-4-O-benzyl-1,2-O-(1-methoxyethylidene)-β-D-mannopyranose. The orthoester could be separated into the exo and endo isomers. Hydrolysis of the orthoester
已经实现了具有 D-甘露糖构型的糖蛋白核心块的合成方案,其标准化为 3,6-二-O-糖基受体并作为 β-D-甘露糖基供体进行立体选择性反应。该合成由甲基 2,3-O-异亚丙基-α-D-甘露糖苷开始,通过苄基化、脱异亚丙基化和 6-O-苄基的选择性乙酰水解得到相应的四乙酸酯,其可转化为 3,6 -二-O-烯丙基-4-O-苄基-1,2-O-(1-甲氧基亚乙基)-β-D-吡喃甘露糖。原酸酯可以分为外型和内型异构体。原酸酯环水解,然后与甲磺酰氯反应得到 3,6-二-O-烯丙基-4-O-苄基-2-O-甲磺酰基-α-D-吡喃甘露糖基氯,通过其 1-O-三氟乙磺酸盐与 2-[4-(对甲苯磺酰氨基)苯基]乙醇反应得到相应的糖苷,β:α 的比例为 3:1。β-糖苷的脱烯丙基化得到适合支化的二醇,并且可以在 6 位选择性反应。