Synthesis of the tetrasaccharide α-d-Glcp-(1→3)-α-d-Manp-(1→2)-α-d-Manp-(1→2)-α-d-Manp recognized by Calreticulin/Calnexin
作者:Emiliano Gemma、Martina Lahmann、Stefan Oscarson
DOI:10.1016/j.carres.2005.09.001
日期:2005.11
The title compound as its methyl glycoside was efficiently synthesized using a block synthesis approach. Halide-assisted glycosidations between 6-O-acetyl-2,3,4-tri-O-benzyl-alpha-D-glucopyranosyl iodide and ethyl 2-O-acetyl-4,6-di-O-benzyl-1-thio-alpha-D-mannopyranoside using triphenylphosphine oxide as promoter yielded, with complete alpha-selectivity, a disaccharide building block in high yield. The
使用嵌段合成方法有效地合成了标题化合物作为其甲基糖苷。6-O-乙酰基-2,3,4-三-O-苄基-α-D-吡喃葡萄糖基碘化物与乙基2-O-乙酰基-4,6-二-O-苄基-1-硫代烃之间的卤化物辅助糖基化使用三苯基氧化膦作为促进剂的β-α-D-甘露吡喃糖苷以完全的α-选择性产生了高产率的二糖结构单元。事实证明,该化合物的过苄基化衍生物是出色的供体,它以NIS / AgOTf促进的偶联方式提供88%的受保护目标四糖与已知的甲基二甘露糖苷受体。然后通过催化氢解脱保护得到目标化合物,总产率为47%。