| 摘要 |
New 3-acetoxy-9 beta, 11 beta-epoxy-1,3,5-pregnatrienes and 3,5-pregnadienes of formula (I) are claimed. (where R1 and R2 are H, OH, aroyloxy, acyloxy or 1-6C alkyl, or together form a 16,17-siopropylidenedioxy gp, R3 is H, halogen, OH, acyloxy, aroyloxy or a sulphonyloxy gp.). Also claimed are process for (a) preparing cpds. (I) and (b) preparing 6 alpha-halo-1,4-pregnadien-3-ones and -4-pregnen-3-ones of formula (II). (where X is halogen). (II) are useful as intermediates for preparing corticosteroids. A specific cpd. (I) is 3,17,21-triacetoxy-9beta, 11beta-epoxy-1,3,5-pregnatrien-20-one. |
