Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
Org Lett. 2023 Sep 1;25(34):6413-6418. doi: 10.1021/acs.orglett.3c02430. Epub 2023 Aug 21.
Herein we report the first total synthesis of a densely functionalized tetrasaccharide repeating unit of O43, which contains rare deoxy amino sugars d-quinovosamine and d-viosamine attached with the rare amino acid -acetyl-l-allothreonine. Synthesis of orthogonally protected rare sugars and unnatural amino acid building blocks, stereoselective construction of three consecutive 1,2- glycosidic linkages, amide coupling, and the presence of five nitrogen atoms dispersed over four sugar units as well as the carboxylic acid functionality make the total synthesis a formidable task.
在此，我们报告了 O43 的一个高度功能化的四糖重复单元的首次全合成，其中含有罕见的脱氧氨基糖 d-奎诺糖胺和 d-粘霉胺，以及罕见的氨基酸 -乙酰-l-allo 苏氨酸。正交保护的稀有糖和非天然氨基酸砌块的合成、三个连续 1,2-糖苷键的立体选择性构建、酰胺偶联以及五个氮原子分散在四个糖单元以及羧酸官能团使得全合成成为一项艰巨的任务。
