Synthetic directions of acidic hexasaccharide repeating unit of the O-antigen of Cronobacter sakazakii HPB 2855 using one pot glycosylation
作者:Rekha Sangwan、Pintu Kumar Mandal
DOI:10.1016/j.tetlet.2018.12.019
日期:2019.1
immobilized on silica (H2SO4-silica) as a Brönsted acid catalyst to work as a promoter. The stereo outcomes of all the glycosylation steps were excellent with satisfactory yield. TEMPOmediated selective oxidation of the primary hydroxyl group has been carried out at the late stage of the synthetic strategy to achieve the required uronic acid motif.
阪崎肠杆菌HPB 2855的O抗原六糖重复单元的合成已通过顺序糖基化和一锅糖基化脱保护技术实现。合成方法依赖于使用对甲氧基苄基醚作为可原位去除的保护基,以显着减少反应步骤的数量。所有糖基化反应都是通过在固定化二氧化硅(H 2 SO 4)的硫酸存在下,使用NIS激活唯一一类简单而稳定的硫糖基供体来完成的。-二氧化硅)作为布朗斯台德酸催化剂起促进剂的作用。所有糖基化步骤的立体效果均极佳,且收率令人满意。TEMPO介导的伯羟基选择性氧化已在合成策略的后期进行,以实现所需的糖醛酸基序。
Synthetic directions towards capsular polysaccharide of Streptococcus pneumoniae serotype 18C
作者:Geeta Karki、Pintu Kumar Mandal
DOI:10.1016/j.tetlet.2019.151153
日期:2019.10
compound after a series of functional group transformations. The synthetic method relies on the use of p-methoxybenzyl ether as an in situ-removable protectinggroup to reduce the number of reaction steps significantly. Here H2SO4-silica has been used successfully as a promoter for all glycosylation reaction. In addition, the synthetic target also contained a free aminogroup at its reducing end, facilitating
已经开发了一种有效的合成策略,用于合成对应于肺炎链球菌血清型18C的荚膜多糖的三糖,四糖嵌段和五糖作为其2-氨基乙基糖苷。已采用一锅糖基化-脱保护,顺序糖基化策略来构建片段和五糖衍生物,然后在进行一系列官能团转化后将其转化为目标化合物。合成方法依赖于使用对甲氧基苄基醚作为可原位去除的保护基,以显着减少反应步骤。这里H 2 SO 4-二氧化硅已成功地用作所有糖基化反应的促进剂。此外,合成靶标在其还原端还包含一个游离氨基,有助于其与其他分子结合,用于各种生物学研究和应用。