4,6-Di-O-Benzylidenyl group-directed preparation of 2-deoxy-2-azido-α-d-galactopyranosides promoted by 3-O-TBDPS
作者:Xing-Yong Liang、Jing Yang、Zhong-Hao Qiu、Lei Wang、Todd L. Lowary、Hua-Jun Shawn Fan
DOI:10.1016/j.carres.2021.108237
日期:2021.2
In this study, we designed a method to prepare 2-deoxy-2-azido-α-d-galactopyranosidic bonds using 4,6-di-O-benzylidenyl-3-O-t-butyldiphenylsilyl protected 2-deoxy-2-azido-1-thio-d-galactopyranoside 5 as donors. The donor 5 gives a good to excellent α-selectivity in the glycosylation with secondary alcohols, which was found to be associated with the benzylidenyl on 4,6-di-O and TBDPS on 3-O of the donor
在这项研究中,我们设计了一种使用4,6-二-O-苄叉基-3-叔丁基二苯基甲硅烷基保护的2-脱氧-2-叠氮基-1制备2-脱氧-2-叠氮基-α-d-吡喃半乳糖苷键的方法。 -硫代-d-吡喃半乳糖苷5作为供体。供体5在与仲醇的糖基化中具有良好的优异的α-选择性,这与供体5的4,6-二-O上的亚苄基和3-O上的TBDPS有关。供体6和7,3-O-TBDPS可以增加硫糖苷的活性,而4,6-二-O-苄基上的孤对增强了gg-协同作用,这在提高立体选择性方面发挥了作用。最后,通过合成含α-半乳糖胺的五糖26证明了该方法。