The first highly stereoselective synthesis of digitoxin is described. The furyl derivative of digitoxigenin was coupled with one unit of digitoxose using our previously described acid catalyzed method. For the second and third glycosylation a new method involving ethyl thioglycosides and 1,3-participation by a p-methoxy benzoate group was developed. As the final step after deprotection of the triglycoside, the 17-furyl group in the steroid aglycone was converted to a butenolide by our oxidative method.
描述了迪吉托辛的首个高度立体选择性合成。迪吉托氧基甾酮的
呋喃衍
生物与一单位的迪吉托糖利用我们先前描述的酸催化方法结合。对于第二和第三个糖基化,开发了一种涉及乙基
硫代糖苷和对
甲氧基苯甲酸酯基团的1,3-参与的新方法。作为最后一步,在去保护三糖苷后,类
固醇缺口中的17-
呋喃基团通过我们的氧化方法转化为
丁烯内酯。