method. ortho-Formylphenyl 1-thio-β-d-galactopyranoside was regioselectively tethered to methyl α-d-glucopyranoside under acidic condition to furnish an 4,6-O-arylidene acetal-linked conjugate. This conjugate can be readily converted to an ether-linked 4-O- or 6-O-derivative by regioselective cleavage of the acetal ring. In the glycosylation reaction, the ether-linked 4-OH conjugate was found to show excellent
提出了一种简便的方法,用于糖基供体和受体之间的区域选择性缀合,以发展区域选择性1,2-顺式糖基化方法。在酸性条件下,将邻甲酰基苯基1-
硫代-β-d-
吡喃半
乳糖苷区域选择性地束缚在甲基α-d-
吡喃
葡萄糖苷上,得到4,6-O-亚芳基
乙缩醛连接的共轭物。通过
缩醛环的区域选择性裂解,该缀合物可以容易地转化为醚连接的4-O-或6-O-衍
生物。在糖基化反应中,发现通过分子内的1,9-转移,醚连接的4-OH缀合物显示出优异的1,2-顺式选择性。