| 摘要 |
FIELD: organic chemistry, steroids, chemical technology. ^ SUBSTANCE: invention relates to an improved method for synthesis of 7alpha-methylsteroids of the general formula (I) wherein R1 means hydrogen atom (-H), -CH3 or -C=CH; R2 means -(CH2)nOH wherein n = 0, 1 or 2. Method involves using copper (Cu(II) acetate or chloride preferably), 1,6-coupled addition of Grignard reagent of the formula CH3MgX wherein X means halogen atom to 4,6-unsaturated 3-ketosteroid of the formula (II) wherein r1 and R2 have above given values and wherein hydroxy-group of steroid of the formula (II) is protected by trialkylsilyl group followed by its treatment with Grignard reagent and removal of a protective group. Method enhances stereoselectivity by the yield of 7alpha-isomer. ^ EFFECT: improved method of synthesis. ^ 18 cl, 3 ex |
