A convenient and divergent approach was developed to prepare diverse bacterial 3‐deoxy‐d‐manno‐oct‐2‐ulosonic acid (Kdo) oligosaccharides containing a Kdo‐α‐(2→4)‐Kdo fragment. The orthogonal protected α‐(2→4) linked Kdo‐Kdo disaccharide 3, serving as a common precursor, was divergently transformed into the corresponding 8‐, 8′‐, and 4′‐hydroxy disaccharides 5, 7, and 14, respectively. Then, these alcohols were glycosylated, respectively, with the 5,7‐O‐di‐tert‐butylsilylene (DTBS) protected Kdo thioglycoside donors 1 or 2 in an α‐stereoselective and high‐yielding manner to afford a range of Kdo oligosaccharides. Finally, removal of all protecting groups of the newly formed glycosides resulted in the desired free Kdo oligomer.

中文翻译：

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包含α-（2→4）-连接的Kdo-Kdo单元的3-脱氧-dmanno-oct-2-ulosonic酸（Kdo）糖苷的发散合成

一种方便的和发散的方式被开发，以制备不同的细菌3-脱氧d -甘露含有KDO-α-（2→4）-Kdo片段-辛-2-糖酸（KDO）寡糖。正交保护的α-（2→4）连接的KDO-KDO双糖3，作为共同的前体，被发散地转化成相应的8-，8'-，和4'-羟基二糖5，7，和14，分别。然后，这些醇是糖基化的，分别与5,7- ø -二-叔-butylsilylene（DTBS）保护的KDO硫糖苷给体1或2以α-立体选择性和高产率的方式提供了一系列Kdo寡糖。最后，除去新形成的糖苷的所有保护基团，得到所需的游离Kdo低聚物。