Synthesis of a Conjugation-Ready, Phosphorylated, Tetrasaccharide Fragment of the O-PS of <i>Vibrio cholerae</i> O139
作者:Sameh E. Soliman、Pavol Kováč
DOI:10.1021/acs.joc.5b02105
日期:2015.11.20
A new pathway to the tetrasaccharide α-Colp-(1→2)-4,6-P-β-d-Galp-(1→3)-[α-Colp-(1→4)]-β-d-GlcpNAc-1-(OCH2CH2)3NH2 has been developed. Glycosylation of 8-azido-3,6-dioxaoctyl 4,6-O-benzylidene-2-deoxy-2-trichloroacetamido-β-d-glucopyranoside with 3,4,6-tri-O-acetyl-2-O-bromoacetyl-α-d-galactopyranosyl bromide afforded the β-linked disaccharide. Debromoacetylation followed by reductive opening of the
一种新的途径,以四糖α-Col中p - (1→2)-4,6- P -β- d -Gal p - (1→3) - [α-Col中p - (1→4)] - β - d -Glc p NAC-1-(OCH 2 CH 2)3 NH 2已经研制成功。8-叠氮基-3,6-二氧杂辛基-4,6-糖基化ø -亚苄基-2-脱氧-2- trichloroacetamido-β- d吡喃葡萄糖苷与3,4,6-三- O-乙酰基-2- ö -bromoacetyl -α- d-半乳糖吡喃糖基溴化物提供了β-连接的二糖。脱溴乙酰化,然后还原性打开亚苄基乙缩醛,得到二糖二醇受体。用2,4-二-O-苄基-α-colitosyl溴化物进行卤化物辅助的糖基化得到1,2-顺式偶联产物。脱乙酰化,然后进行区域选择性磷酸化,得到异构的(R,S)-(P)-4 II,6 II-环磷酸酯,其通过一步催化(Pd / C)氢化/氢解反应整体脱