An efficient synthesis of a structurally congested tetrasaccharide portion from the cellulosome produced by Clostridium thermocellum has been accomplished through a stepwise glycosylation strategy. The key steps for the synthesis include the stereocontrolled construction of a range of challenging 1,2‐cis glycosidic linkages. The 5‐O‐(2‐quinolinecarbonyl) substituted D‐galactofuranosyl thioglycoside 2, 4,6‐O‐benzylidene protected 2‐azido‐2‐deoxyglucose thioglycoside 3 c, and 4,6‐O‐benzylidene protected D‐galactopyranosyl thioglycoside 4 were employed as glycosyl donors, respectively, for the high‐yielding and stereoselective formation of the corresponding 1,2‐cis‐α‐Galf, α‐GlcNAc, and α‐Galp linkages.

中文翻译：

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从热纤梭菌产生的纤维素体立体选择性合成四糖片段。

通过逐步糖基化策略已经从热纤梭菌产生的纤维素小体中有效地合成了结构上拥挤的四糖部分。合成的关键步骤包括立体控制一系列具有挑战性的1,2-顺式糖苷键的构建。5- Ô - （2-喹啉羰基）取代的d-galactofuranosyl硫代糖苷2，4,6- ø -亚苄基保护的2-叠氮基-2-脱氧葡萄糖硫代糖苷3c中，与4,6- ö -亚苄基保护的d吡喃半乳糖硫苷4分别用作糖基供体，用于高产和立体形成相应的1,2-顺式-α-Gal的˚F，α-GlcNAc的，和α-Gal的p键。