| 摘要 |
<p>The invention comprises pregn-4-en-3-one derivatives having the general formula: <FORM:0970588/C1/1> in which R6 represents two hydrogen atoms or the methylene group =CH2, Y indicates an hydrogen atom or an acyl group derived either from an organic carboxylic acid having from 1-18 carbon atoms or from a mineral acid, and R7 represents the groups =H(OH) or the oxygen atom =O and their corresponding 3-ketal derivatives, and processes for the preparation thereof wherein a 3-ketal of pregn-4-ene-3,11,21-trione having the formulae: <FORM:0970588/C1/2> <FORM:0970588/C1/3> is reduced e.g. with sodium borohydride to obtain the corresponding 21-hydroxy compound which is deketalized at 3-position by treatment with an acid e.g. H2SO4, HCl. The products so obtained may be esterified by treatment with an acylating agent derived from an organic carboxylic or mineral acid e.g. HNO3. The 11-hydroxy compounds are preferably obtained by reduction of the 3,11-dione e.g. with lithium aluminium hydride to form the 3,11b -dihydroxy compound and reoxidizing e.g. with MnO2 to yield a 3-keto-11b -hydroxy compound. Specification 970,587 also is referred to.</p> |
