Experimental and theoretical study of the O3/O4 regioselectivity of glycosylation reactions of glucopyranosyl acceptors
作者:Enrique A. Del Vigo、Carlos A. Stortz、Carla Marino
DOI:10.1016/j.tet.2020.131719
日期:2020.12
The knowledge of the regioselectivity between different hydroxyl groups of glycosyl acceptors is valuable in planning simple strategies for the synthesis of oligosaccharides, minimizing the use of protecting groups. With the aim of obtaining deeper knowledge on this subject, we analyzed the relative reactivity of the OH-3 and OH-4 groups of 2,6-di-O-protected methyl α- and β-glucopyranosides in glycosylation
糖基受体的不同羟基之间的区域选择性的知识对于规划寡糖合成的简单策略,最大限度地减少保护基的使用非常有价值。为了获得对该主题的更深入的了解,我们分析了2,6-di- O的OH-3和OH-4基团的相对反应性糖基化反应中保护的甲基α-和β-吡喃葡萄糖苷。通过简单的程序制备糖基受体,并将半乳糖-吡喃糖基和呋喃糖基三氯乙酰亚氨酸酯评估为糖基供体。将实验结果与通过分子建模方法获得的结果进行对比。分子模型和实验结果基本吻合。已经表明,通过选择正确的端基异构体和保护基团,可以使用适当的葡糖基受体选择性地安装1→3或1→4键。