Synthesis of the repeating trisaccharide unit of the cell wall lipopolysaccharide of Escherichia coli type 8
作者:Sajal K. Maity、Swarupananda Maity、Amarendra Patra、Rina Ghosh
DOI:10.1016/j.tetlet.2008.07.089
日期:2008.10
3,4,6-tri-O-benzyl-α-d-mannopyranosyl-(1→2)-3,4,6-tri-O-benzyl-α-d-mannopyranoside in very good yield and excellent β-selectivity. Pd/C catalyzed hydrogenation of the latter finally afforded the repeating trisaccharide of Escherichia coli 8 O-antigen as its methyl glycoside.
NIS / TfOH介导的甲基3,4,6-三-O-苄基-α-d-甘露吡喃糖苷与苯基2 - O-乙酰基-3,4,6-三-O-苄基-1-硫代-α-糖基化d-甘露吡喃糖苷以优异的产率和α-选择性提供了相应的二糖衍生物。随后用BSP / TF反应相同的脱乙酰普伦2 O形预活化苯基-4,6- ø -亚苄基-2,3-二- ö苄基-1-硫代α-d-D-吡喃甘露糖苷生成4,6- O-亚苄基-2,3-二-O-苄基-β-d-甘露吡喃糖基-(1→2)-3,4,6-三-O-苄基-α-d-甘露吡喃糖基-(1→2)- 3,4,6-三-O-苄基-α-d-甘露吡喃糖苷具有非常好的收率和出色的β-选择性。后者的Pd / C催化氢化最终提供了大肠杆菌8 O-抗原的重复三糖作为其甲基糖苷。