An Effective Sialylation Method Using<i>N</i>-Troc- and<i>N</i>-Fmoc-protected β-Thiophenyl Sialosides and Application to the One-pot Two-step Synthesis of 2,6-Sialyl-T Antigen
We describe an efficient sialylation method using β-thiosialosides with various N-protecting groups. Modification of the C-5 amino group of β-thiosialosides into N-Fmoc and N-Troc derivatives enhanced their reactivity in glycosidation. In addition, a minimum amount of MS-3 A was effective to improve the yield of α-linked sialoside. Branched type one-pot glycosylation initiating glycosidation of the
我们描述了一种使用具有各种 N 保护基团的 β-硫代唾液酸的有效唾液酸化方法。将 β-硫代唾液酸苷的 C-5 氨基修饰为 N-Fmoc 和 N-Troc 衍生物增强了它们在糖苷化中的反应性。此外,最少量的 MS-3 A 可有效提高 α-连接的唾液酸苷的产率。支链型一锅糖基化在伯醇处启动 N-Troc 保护的 β-噻吩唾液酸苷的糖苷化,以良好的产率提供受保护的 2,6-唾液酸-T 抗原,将其转化为完全脱保护的糖基氨基酸。
One-Pot Synthesis of Sialo-Containing Glycosyl Amino Acids by Use of anN-Trichloroethoxycarbonyl-?-thiophenyl Sialoside
We describe an efficient synthesis of 2,6- and 2,3-sialyl T antigens linked to serine in a one-pot glycosylation. We first investigated the glycosidation of thiosialosides by varying the N-protecting group. Modification of the C-5 amino group of beta-thiosialosides into the N-9-fluorenylmethoxycarbonyl, N-2,2,2-trichloroethoxycarbonyl (N-Troc), and N-trichloroacetyl derivatives enhanced the reactivity