GB773926A - Improvements relating to pregnane compounds - Google Patents

Abstract

The invention comprises pregnane-5a ,11b ,-17a ,21-tetrol-3,20-dione and the 21-acetate thereof, and the 3,20-bisethylene ketal derivatives of both compounds, and a process for producing pregnane compounds by reducing D 5 - pregnene - 11b ,17a ,21 - triol - 3,20 - dione - 5a ,6a - oxide 21-lower fatty acid ester 3,20-bis-lower alkylene ketal in an inert organic solvent, e.g. tetrahydrofuran, with lithium aluminium hydride to form a pregnane-5a ,11b ,17a ,21-tetrol -3,20 - dione 3,20 - bis - lower alkylene ketal, and, if desired, hydrolysing with acid said ketal to produce pregnane-5a ,11b ,17b ,21-tetrol-3,20-dione. The above process may be modified in that the D 5-pregnene-11b ,17a ,21-triol-3,20-bis -lower alkylene ketal is prepared from a bis-lower alkylene ketal of a hydrocortisone lower fatty acid ester by reaction with an organic per-acid. The lower fatty acid acyl radicals and the lower alkylene ketal radicals contain 1 to 4 carbon atoms, suitable acyl radicals being acetyl, propionyl and butyryl radicals and suitable alkelene radicals being ethylene ketal, propylene ketal and methylpropylene radicals. The reaction with the organic peracid may be carried out with perbenzoic or monoperphthalic acid at room temperature in an inert organic solvent such as chloroform, carbon tetrachloride or ethyl acetate, to form a mixture of the 5a ,6a -oxide and 5b ,6b -oxide which may be resolved by chromatography or used as a mixture for the following reduction step with lithium aluminium hydride. In the examples pregnane-11b ,17a ,21-triol - 3,20 - dione - 5a ,6a - oxide 21 - acetate-3,20-bisethylene ketal and the corresponding 5b ,6b -oxide are prepared. The mixture of oxides or the 5a ,6a -oxide are reduced with lithium aluminium hydride to form pregnane-5a ,11b ,17a ,21 - tetrol - 3,20 - dione 3,20 - bis-ethylene ketal which is acetylated to form the corresponding 21-acetate, or treated with sulphuric acid to form pregnane-5a ,11b ,17a ,21-tetrol-3,20-dione which is acetylated to form the corresponding 21-acetate. The pregnane-5a ,-11b ,17a ,21 - tetrol - 3,20 - dione 3,20 - bis-ethylene ketal 21-acetate is also saponified with alcoholic potassium hydroxide to form the corresponding 21-hydroxy compound.