Bhetuwal Bishwa Raj, Wu Fenglang, Meng Shuai, Zhu Jianglong
Department of Chemistry and Biochemistry and School of Green Chemistry and Engineering, The University of Toledo, 2801 West Bancroft Street, Toledo, Ohio 43606, United States.
J Org Chem. 2020 Dec 18;85(24):16196-16206. doi: 10.1021/acs.joc.0c02370. Epub 2020 Nov 17.
Cesium carbonate-mediated anomeric O-alkylation of various protected 2-azido-2-deoxy-d-mannoses with primary triflate electrophiles afforded corresponding 2-azido-2-deoxy-β-mannosides in good yields and excellent anomeric selectivity. In addition, 1,3-dibromo-5,5-dimethylhydantoin was found to be the optimal oxidant for preparation of those 2-azido-2-deoxy-d-mannoses from their corresponding thioglycosides. The utilization of this method was demonstrated in the synthesis of a tetrasaccharide fragment of teichuronic acid containing -acetyl-β-d-mannosaminuronic acid (ManNAcA).
碳酸铯介导的各种受保护的2-叠氮基-2-脱氧-D-甘露糖与伯三氟甲磺酸酯亲电试剂的端基O-烷基化反应,以良好的产率和优异的端基选择性得到了相应的2-叠氮基-2-脱氧-β-甘露糖苷。此外,发现1,3-二溴-5,5-二甲基海因是由相应的硫代糖苷制备这些2-叠氮基-2-脱氧-D-甘露糖的最佳氧化剂。该方法在含有N-乙酰基-β-D-甘露糖胺糖醛酸(ManNAcA)的磷壁酸四糖片段的合成中得到了应用。