| 摘要 |
<p>1,184,104. 5α- Halo - 6# - (acyloxy and hydroxy) - steroids. SYNTEX CORP. 13 April, 1967 [25 April, 1966], No. 17023/67. Heading C2U. 5α- Halo - 6# - acyloxy - steroids are prepared from #<SP>5</SP>-steroids and positive halogen releasing agents in anhydrous hydrocarbon carboxylic acids of less than 12 carbon atoms, and are converted to 5α-bromo-6#-hydroxy-steroids by reaction with a base to give 5#,6#-oxido-steroids and treatment of these with hydrogen bromide. The starting materials may be regenerated from the mother liquors of the first reaction process by treatment with zinc in the presence of a carboxylic acid, and the 5,6-epoxides may be regenerated from the mother liquors of the last process by treatment with a strong base. The preferred starting materials are 3#-acylates, which are hydrolysed to 3#-ols during the epoxide formation; they are preferably re-acylated before the hydrobromination.</p> |
