| 摘要 |
A process for the partial reduction of C21-steroid carboxylic acids and their esters to C21-steroid alcohols and new C21-steroid alcohols DELTA 4,17(20)-C21-steroid carboxylic acids optionally containing further double bonds in the 1- and/or 9(11)-position and their esters corresponding to general formula I below <IMAGE> (I) in which R represents hydrogen or a hydrocarbon radical and A represents hydrogen, hydroxyl or, together with the C-atom substituted by A, a carbonyl group and in which, finally, the substituent A may even be replaced by an additional olefinic double bond in the 9(11)-position, are reacted with diisobutyl aluminium hydride without the A-ring in the steroid skeleton being blocked in such quantities that all the oxygen-containing functional groups are reduced to the hydroxyl group. The aluminium-containing intermediate reaction product is then subjected to the selective Oppenauer oxidation to form the 3-keto compound. The 3-oxo-C21-steroid alcohols may be obtained in high yields in this way. The process is suitable for the preparation of pharmacologically active steroid compounds having the 17,21-diol-20-one configuration. It enables the new compuonds, pregna-1,4,17(20)-triene-3-one-21-ol and pregna-1,4,9(11),17(20)-tetraene-3-one-21-ol and their 21-acetoxy compounds, to be obtained.
|
