O -benzyl-2-deoxy- α , and β- d -galactopyranoside, respectively, which served as acceptors in glycosylation reactions with variously activated derivatives of methyl 2-O- benzoyl -3-O- benzyl -4-O- chloroacetyl- l -idopyranuronate . Condensation of the chloride derivative promoted by silver triflate led unexpectedly to the formation of the β-linked disaccharide, whereas the trichloroacetimidoyl derivative
摘要通过三步操作,将苄基2-乙酰
氨基-2-脱氧-α和β-d-
吡喃
葡萄糖苷高产率地转化为相应的d-半乳
糖类似物。这些后来以直接的方式分别转化为苄基2-乙酰
氨基-4-O-乙酰基-6-O-苄基-2-脱氧-α和β-d-
吡喃半
乳糖苷,它们在糖基化反应中以各种方式用作受体。活化的2-O-苯甲酰基-3-O-苄基-4-O-
氯乙酰基-1-
碘吡喃醛酸酯的衍
生物。由
三氟甲磺酸银促进的
氯化物衍
生物的缩合出乎意料地导致了β-连接的二糖的形成,而三
氯乙
酰亚胺基衍
生物以63%的收率提供了预期的α-连接的二糖。随后进行O-脱
氯乙酰化,然后在糖醛酸部分的O-4处进行4-甲氧基苄基化,