Synthesis of α-Manp-(1→2)-α-Manp-(1→3)-α-Manp-(1→3)-Manp, the tetrasaccharide repeating unit of Escherichia coli O9a, and α-Manp-(1→2)-α-Manp-(1→2)-α-Manp-(1→3)-α-Manp-(1→3)-Manp, the pentasaccharide repeating unit of E. coli O9 and Klebsiella O3
作者:Langqiu Chen、Yuliang Zhu、Fanzuo Kong
DOI:10.1016/s0008-6215(02)00011-3
日期:2002.3
3- O -allyl-2,4,6-tri- O -benzoyl-α- d -mannopyranosyl trichloroacetimidate ( 5 ). Condensation of 5 with methyl 4,6- O -benzylidene-α- d -mannopyranoside ( 6 ) selectively afforded the (1→3)-linked disaccharide 7 . Benzoylation of 7 , debenzylidenation, benzoylation, and deallylation gave methyl 2,4,6-tri- O -benzoyl-α- d -mannopyranosyl-(1→3)-2,4,6-tri- O -benzoyl-α- d -mannopyranoside ( 11 ) as the
摘要大肠杆菌O9a的四糖重复单元,α-d -Man p-(1→2)-α-d -Man p-(1→3)-α-d -Man p-(1→3)-d -Man p和大肠杆菌O9和克雷伯菌O3的五糖重复单元,α-d -Man p-(1→2)-α-d-Man p-(1→2)-α-d -Man p合成了-(1→3)-α-d-Manp-(1→3)-d-Man p作为甲基糖苷。因此,对-甲氧基苯基α-d-甘露吡喃糖苷经由二丁基锡中间体的选择性3-O-烯丙基化以良好的产率得到了对-甲氧基苯基3-O-烯丙基-α-d-甘露吡喃糖苷(2)。苯甲酰化(→3),然后除去1- O-甲氧基苯基(→4),然后进行三氯乙酰亚胺化,得到3- O-烯丙基-2,4,6-三-O-苯甲酰基-α-d-甘露酰吡喃糖基三氯乙酰胺酸酯(5 )。5与甲基4,6-O-亚苄基-α-d-甘露吡喃糖苷(6)缩合选择性地提供(1→3)-连接的二糖7。7的苄基