Synthesis of 11β-(4-dimethylaminophenyl)-17β-hydroxy-17α- (3-methyl-1-butynyl)-4, 9-estradien-3-one and 11β-(4-acetophenyl)- 17β-hydroxy-17α-(3-methyl-1-butynyl)-4, 9-estradien-3-one: two new analogs of mifepristone (RU-486)

From the structure activity relationship, two new analogs, 2 and 3, of the potent progesterone antagonist mifepristone 1 have been designed. The syntheses of these two analogs have been achieved in eleven steps through modified synthetic sequences and improved procedures starting from (+)-estrone. In comparison with mifepristone 1, the relative binding affinities of compound 2 for the progesterone receptor was found to be more, whereas that of compound 3 was less.