Efficient Synthesis of Man<sub>2</sub>, Man<sub>3</sub>, and Man<sub>5</sub> Oligosaccharides, Using Mannosyl Iodide Donors<sup>1</sup>
作者:Son N. Lam、Jacquelyn Gervay-Hague
DOI:10.1021/jo051360d
日期:2005.10.1
resulting from attack at the C-2 acetate. However, upon warming to room temperature the orthoacetate quantitatively rearranged to the desired oligosaccharide. Employing a 3,6-dihydroxy acceptor and subjecting it to double glycosidation quickly afforded high mannose sugars in nearly quantitative yields. Glycosyl iodide donors offer advantages over previously reported chloride donors as the reactions are
已经开发了使用正交保护的糖基碘碘供体制备Man 3和Man 5寡糖的高效方案。C-2- O的糖基化在-40°C的三氟甲磺酸银存在下,β-乙酰基甘露糖基碘化物供体开始生成所需的α-连接的甘露糖苷和原乙酸酯的混合物,该混合物由对C-2乙酸酯的攻击引起。但是,温热至室温后,原乙酸酯定量地重排为所需的寡糖。使用3,6-二羟基受体并使其经受双重糖苷化作用,很快就以几乎定量的产量提供了高甘露糖。糖基碘化物供体比先前报道的氯化物供体具有优势,因为反应更快,产率更高并且在高阶构建体中不会减少。这些研究继续消除了糖基碘化物反应性太强以至于不能用于合成的观念。