METHOD OF PREPARING CORTICOSTEROIDS Russian patent published in 2000 - IPC

FIELD: organic synthesis. SUBSTANCE: described is synthesis of steroid drugs, more particularly corticosteroids of general formula: wherein R¹ is α or -β-OH- or H; R² is H or OH or F, or together R¹, R² is double bond; R³- is H or CH₃ or F; R⁴ is H or OH; R⁵ is α or β-CH₃ or H; R⁶ is H or Ac from sterols of vegetable and animal origin. 3,17-D ketoandrostanes of general formula: are subjected to cyanation, 17-α-OH is subjected to protection with alkyl- vinyl ether, 3-keto group is subjected to protection with unsubstituted or 2-substituted, or 2,2-disubstituted propylene ketal followed by hydrolysis. The resulting compound is subjected to alkylation at CN-position and halogentation at C21-position by direct iodination followed by substitution of iodine for oxy- or acetoxy group. Method makes it possible to increase yield of the desired product. EFFECT: more efficient preparation method. 3 cl, 1 dwg, 7 ex