Methyl and benzyl 2,3,4-tri-O-benzyl-d-glucopyranuronates, prepared from d-glucurono-6,3-lactone, afforded selectively the corresponding α-glucopyranosiduronates by the aid of the condensing reagent system composed of p-nitrobenzenesulfonyl chloride, silver trifluoromethanesulfonate, and triethylamine. Using this method, O-α-d-glucopyranuronosyl-(1→3)-O-α-l-arabinofuranosyl-(1→3)-d-xylopyranose, one of the minimal component units in the structure of plantago-mucilage A from the seeds of Plantago asiatica Linné constituting a Chinese medicine : chegianzi [].
在
对硝基苯磺酰氯、
三氟甲磺酸银和
三乙胺组成的缩合试剂体系的帮助下,由 d-
葡萄糖醛酸-6,3-内
酯制备的 2,3,4-三-O-
苄基-d-
吡喃
葡萄糖醛酸甲
酯和苄
酯选择性地得到了相应的 α-
吡喃
葡萄糖苷酸盐。利用这种方法,从构成中药车前子的车前子种子中提取出了车前子粘液 A 结构的最小组成单位之一--O-α-d-
吡喃
葡萄糖呋喃糖基-(1→3)-O-α-阿拉伯
呋喃糖基-(1→3)-d-
吡喃
木糖[]。