Ginkgolide B (1b) has been glucosylated in THF with the glucosylidene-derived diazirine 2 under thermal or photochemical conditions. Depending on the amount of 2, we obtained either monoglucosides (5–8), diglucosides (13–17), or triglucosides (21–23). In keeping with earlier results, the use of THF as solvent led mostly to β-D-glucosides. The modest regioselectivity in the formation of the monoglucosides
银杏内酯B(1b)已经在热或光
化学条件下与
葡糖亚砜衍生的重氮2一起在THF中进行了糖基化。根据2的量,我们获得了
单糖苷(5 – 8),二糖苷(13 – 17)或三糖苷(21 – 23)。与先前的结果一致,使用THF作为溶剂主要导致β-D-
葡糖苷。基于1b的分子内和分子间H键合的OH基团的相对动力学酸性,合理化了在OC(1)或OC(10)处被糖基化的
单糖苷形成的适度区域选择性。。
单糖苷的叔HOC(3)比仲HOC(1)或HOC(10)(H键合)更容易被糖基化。3.5当量的糖苷化。的2导致triglucosides,与三-β-d
葡萄糖苷21(42%),为主要产物。催化氢化,得到游离苷9 - 12,18 - 20,和24。二-和triglucosides易溶H中2 O. Glucosidation与
银杏内酯-A衍生的叔醇25 2得到的β型d-异头
葡糖苷的93%26。相似地,由内酰胺基二嗪34衍生的