glycosylation of steroids was established using a modified Koenigs-Knorr procedure. Peracetylated beta-glycosides were synthesized by reaction of cardenolides, various pregnanes and 23-nor-5,20(22)E-choldienic acid at room temperature with the peracetylated 1-bromo derivatives of D-glucose, D-galactose, D-fucose and cellobiose. Subsequent deprotection was performed by alkaline hydrolysis with sodium methoxide
使用改良的 Koenigs-Knorr 程序建立了一种快速有效的类
固醇糖基化程序。全乙酰化β-糖苷是通过cardenolides、各种孕烷和23-nor-5,20(22)E-胆二
烯酸在室温下与
D-葡萄糖、
D-半乳糖、
D-岩藻糖的过乙酰化1-
溴衍
生物反应合成的和
纤维二糖。随后通过
甲醇钠碱
水解进行
脱保护。各个糖苷的结构通过NMR技术确定。完整的方案被证明在所有阶段对糖部分和甾体核都是非破坏性的。Cardenolides 的 γ-不饱和内
酯环显示保持完整,没有观察到 C-14 不饱和化合物的形成。