| 摘要 |
<p>Crystalline cpds. are of formula : (where R is -CO.Me or ). The cpds. are inters. for steroids such as holantogenin but have never been isolated as stable crystalline solids. 3 beta-Acetoxy-5 alpha-20-ol is treated with iodine in a solvent such as cyclohexane to give I(R = -CH.Me OH ) which in turn, is converted into I(R = -CO.Me) by oxidn. with CrO3 or Kiliani's reagent. These pure inters. may be used for prepg. high yields of steroids such as 18-hydroxyprogesterone, a known diuretic, without going via the 18,20-epoxy derivs. which give lower yields.</p> |
