Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
Org Lett. 2020 Oct 16;22(20):8018-8022. doi: 10.1021/acs.orglett.0c02961. Epub 2020 Sep 29.
Synthesis of bacterial cell surface l--d--heptose (l,d-Hep)- and d--d--heptose (d,d-Hep)-containing higher carbon sugars is a challenging task. Here, we report a convenient and efficient approach for the synthesis of the l,d-Hep and d,d-Hep building blocks. Using l-lyxose and d-ribose as starting materials, this approach features diastereoselective Mukaiyama-type aldol reactions as the key steps. On the basis of the synthetic l,d-Hep and d,d-Hep building blocks, we achieved the first stereoselective synthesis of the unique α-l,d-Hep-(1→3)-α-d,d-Hep-(1→5)-α-Kdo core trisaccharide of the lipopolysaccharide of O2.
细菌表面 l--d--庚糖（l,d-Hep）和 d--d--庚糖（d,d-Hep）的合成含有更高的碳糖是一项具有挑战性的任务。在这里，我们报告了一种方便有效的方法来合成 l,d-Hep 和 d,d-Hep 砌块。以 l-苏糖和 d-核糖为起始原料，该方法的关键步骤是立体选择性 Mukaiyama 型羟醛缩合反应。基于合成的 l,d-Hep 和 d,d-Hep 砌块，我们首次立体选择性地合成了脂多糖的独特的α-l,d-Hep-(1→3)-α-d,d-Hep-(1→5)-α-Kdo 核心三糖。
