A building block approach to the synthesis of a family of S-linked α-1,6-oligomannosides
作者:Tyson Belz、Spencer J. Williams
DOI:10.1016/j.carres.2016.04.015
日期:2016.6
The syntheses of α-1,6-S-linked methyl di-, tetra- and hexamannosides are reported. The sulfur linkages are generated through coupling of thiolates (derived from anomeric thioacetates or isothiouronium bromides) with 6-deoxy-6-iodo sugars. Two approaches are detailed that involve [2 + 2 + 2] construction from either the reducing end or the non-reducing end. In constructing from the reducing end, coupling
报道了α-1,6-S-连接的甲基二,四和六甘露糖苷的合成。硫键是通过将硫醇盐(衍生自异头硫代乙酸盐或异硫脲溴化铵)与6-脱氧-6-碘糖偶联而生成的。详细介绍了两种方法,它们涉及从还原性端或非还原性端开始的[2 + 2 + 2]构造。在还原端的构建中,将二糖硫代乙酸盐与6'-碘还原端二糖偶联,然后将所得四糖活化为6'''-碘化物,并与相同的二糖硫代乙酸盐反复偶联,得到S-连接的六糖,以及中间的二糖和四糖。另一方面,从非还原端进行的构建涉及上述二糖硫代乙酸酯与异头S-三苯甲基保护的6'-碘二糖的偶联。将所得的S-三苯甲基四糖转化为四糖硫代乙酸酯,将其与相同的异头S-三苯甲基保护的6'-碘二糖偶联,得到六糖,将其精制为甲基硫代糖苷。所开发的方法学可能被证明可用于构建其他S-连接的寡糖。