Synthesis of<i>β</i>-D-Ribofuranosyl-(1→3)-<i>α</i>-L-rhamnopyranosyl-(1→3)-L-rhamnopyranose by in situ Activating Glycosylation Using 1-OH Sugar Derivative and Me<sub>3</sub>SiBr–CoBr<sub>2</sub>–Bu<sub>4</sub>NBr–Molecular Sieves 4A System
作者:Motoko Hirooka、Yoko Mori、Akiko Sasaki、Shinkiti Koto、Yoshika Shinoda、Aya Morinaga
DOI:10.1246/bcsj.74.1679
日期:2001.9
β-d-Ribofuranosyl-(1→3)-α-l-rhamnopyranosyl-(1→3)-l-rhamnopyranose, the trisaccharide repeating unit of the C. freundii O28,1c O-specific polysaccharide, was synthesized using in situ activating glycosylation of the 1-OH sugar derivatives and a reagent mixture of trimethylsilyl bromide, cobalt(II) bromide, tetrabutylammonium bromide, and molecular sieves 4A. Regioselective tritylation was useful for synthesizing the 3-OH derivatives of methyl, allyl, and benzyl α-l-rhamnosides.
β-d-核糖呋喃糖-(1→3)-α-l-鼠李糖琥珀糖-(1→3)-l-鼠李糖,作为C. freundii O28,1c O特异性多糖的三糖重复单元,采用原位活化糖苷化的方法合成,涉及1-OH糖衍生物和三甲基硅基溴、钴(II)溴化物、四丁基溴化铵及4A分子筛的试剂混合物。区域选择性三苯基甲基化对于合成甲基、烯丙基和苄基α-l-鼠李糖苷的3-OH衍生物非常有效。