| 摘要 |
Cpds. of formula (I):- (where R1 = 1-4C alkyl; R2 is O or (betaP)(alphaQ), where P is free, esterified or etherified OH and Q is H, alkyl, alkenyl or alkynyl (all =4C); R3 is OH, alkoxy, acyloxy, H, alkyl or acyl) are prepd. by reaction of a cpd. (II), with activated oxygen to give the DELTA6-5alpha-hydroperoxy steroid which can then be reduced to the DELTA6-5alpha-hydroxy-steroid and/or substituents introduced and posn. 17 and/or the OOH or OH gps. esterified or etherified. Oxygenation can be effected by irradiating (II) with visible or UV light in the presence of O2 and a sensitiser or by heating with a substd. phosphite-ozonide, esp. triphenyl phosphite ozonide. Cpds. (I) have progestational ovulation-inhibiting, pregnancy-maintaining and oestrogenic activity. |
