-3-O-(2,3,4,6-tetra-O-acetyl-β-d-galactopyranosyl)-α-d-galactopyranosyl bromide (11) in an over-all yield of 86%. Compounds 9 and 11 are suitable glycosyl donors for introduction of the β-d-Gal p-(1 → 3)-β- and -α-d-Gal pNAc groups.
将2-(三甲基甲
硅烷基)乙基2-
叠氮基-4,6-O-亚苄基-2-脱氧-β-d-
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乳糖苷(4)与苯基2,3,4,6-四-O-乙酰基-1-糖基化
硫代-β-d-
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乳糖苷得到2-(三甲基甲
硅烷基)乙基2-
叠氮基-4,6-O-亚苄基-2-脱氧-3-O-(2,3,4,6-四-O-乙酰基- β-d-
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乳糖苷)-β-d-
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乳糖苷(6),产率为99%。除去亚苄基和乙酰化得到关键中间体2-(三甲基甲
硅烷基)乙基4,6-二-O-乙酰基-2-
叠氮基-2-脱氧-3-O-(2,3,4,6-四- O-乙酰基-β-d-
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乳糖基)-β-d-
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乳糖基)(7),将其转化为甲基4,6-二-O-乙酰基-2-脱氧-2-邻苯二甲
酰亚胺基-3-O-(2分两个步骤制备(3,4,6-四-O-乙酰基-β-d-
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乳糖苷)-1-
硫代-β-d-
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乳糖苷(9),总产率为69%。同样地,将7分两步转化为4,6-二-O-乙