Kurosawa T, Ikegawa S, Chiba H, Ito Y, Nakagawa S, Kobayashi K, Tohma M
Faculty of Pharmaceutical Sciences, Higashi-Nippon-Gakuen University, Hokkaido, Japan.
Steroids. 1992 Sep;57(9):426-9. doi: 10.1016/0039-128x(92)90095-q.
18,20-Epoxy-11 beta,17 alpha,20 beta,21-tetrahydroxypregn-4-en-3-one was synthesized by the application of hypoiodite reaction to the cortisol acetonide. The intermediary 18-iodo derivative was converted to the 11-oxo steroid by chromic acid prior to silver ion-assisted solvolysis. Removal of the protective group with hydrochloric acid was finally carried out to give the desired 11 beta,17 alpha,18,21-tetrahydroxypregn-4-ene-3,20-dione as the hemiacetal form. 18,20-Epoxy-11 beta-17 alpha,20 beta,21- tetrahydroxypregna-1,4-dien-3-one was also prepared from prednisolone through a similar reaction sequence.
通过对皮质醇丙酮化物应用次碘酸盐反应合成了18,20-环氧-11β,17α,20β,21-四羟基孕-4-烯-3-酮。在银离子辅助溶剂解之前，先通过铬酸将中间产物18-碘衍生物转化为11-氧代甾体。最后用盐酸除去保护基团，得到所需的半缩醛形式的11β,17α,18,21-四羟基孕-4-烯-3,20-二酮。18,20-环氧-11β-17α,20β,21-四羟基孕-1,4-二烯-3-酮也通过类似的反应序列由泼尼松龙制备得到。
