| abstract |
Obtained 11,17,21 trihydroxypregna-4-ene-3,20-dione of formula I: (see formula) by treating 17? -Hydroxyprogesterone with picrolidine in a molar ratio of about 1: 1 at boiling temperature in methanol , then the resulting enamine is treated with inorganic acid, preferably perchloric acid at a temperature of 15-20 ° C, to obtain the enamine salt which is brought into contact with bromine at a temperature of 30-33 ° C, the brominated derivative which is then subjected to heating with water in the presence of alkaline metal carbonate at 30 ° C to give the dione derivative which is reacted with alkaline metal acetate at the boiling temperature to give 21-acetoxy-1x -hydroxy-pregna-4-ene-3,20-dione, which is treated with acetic anhydride at boiling temperature in the presence of perchloric acid or p-toluenesulfonic acid and ethyl acetate to obtain the corresponding diacetate and triacetate which are subject to hydroxylation at position 11 through treatment microbial, in a known way. |