Synthesis of a 2,3,4-Triglycosylated Rhamnoside Fragment of Rhamnogalacturonan-II Side Chain A Using a Late Stage Oxidation Approach
作者:Anne-Laure Chauvin、Sergey A. Nepogodiev、Robert A. Field
DOI:10.1021/jo0482864
日期:2005.2.1
RG-II, a key component of plant primary cell walls, is known to exist as a dimer formed by means of borate diester cross-links between apiosyl residues of one of its constituent side-chain oligosaccharides. Described herein is the strategy for the synthesis of the branched tetrasaccharide α-d-GalA-(1→2)-[β-d-GalA-(1→3)]-[α-l-Fuc-(1→4)]-α-l-Rha-OMe, an RG-II fragment that is linked to the apiosyl residue
果胶多糖 RG-II 是植物初生细胞壁的关键成分,已知以二聚体的形式存在,该二聚体是通过其组成侧链寡糖之一的仙人掌残基之间的硼酸二酯交联形成的。本文描述的是合成支链四糖α - d -GalA-(1→2)-[β- d - GalA-(1→3)]-[α -1- Fuc-(1→4)的策略] -α- l -Rha-OMe,一种 RG-II 片段,与被认为是 RG-II 二聚体中硼酸盐络合的原因的 apiosyl 残基相连。源自 4 - O-甲氧基苄基-α- d甲酯的关键 2,3-原乙酸酯的鼠李糖苷受体的迭代糖基化-吡喃鼠李糖苷提供受保护的四糖。随后通过去除保护基团随后通过TEMPO介导的将吡喃半乳糖基残基氧化为吡喃半乳糖醛酸来制备目标二羧酸糖。