Mifepristone Dioxolane Impurity

estr-9-en-3-one,11-[4-(dimethylamino)phenyl]-5,17-dihydroxy-17-(1-propynyl)-, cyclic1,2-ethanediyl acetal, (5a,11b,17b)- (9ci) ; mifepristone related compound ; 11β-[(4-n,n-dimethylamino)phenyl]-17α-(propyn-1-ynyl)-3,3-ethylendioxy-estra-9-en-5α,17β-diol ; 3,3-[1,2-ethanediyl-bisoxy]-11-[4-(n,n-dimethylamino)-phenyl]-17-(prop-1-ynyl)-9-estrene-5,17-diol ; estr-9-en-3-one, 11-[4-(dimethylamino)phenyl]-5,17-dihydroxy-17-(1-propynyl)-, cyclic 1,2-ethanediyl acetal, (5a,11b,17b)- ; 11beta-[(4-n,n-dimethylamino)phenyl)]-17alpha-(propyn-1-ynyl)-3,3-ethylendioxy-estra-9-en-5alpha,17beta-diol ; spiro[3h-cyclopenta[a]phenanthrene-3,2'-[1,3]dioxolane],estr-9-en-3-one deriv. ; (5a,11b,17b)-11-[4-(dimethylamino)phenyl]-5,17-dihydroxy-17-(1-propynyl)estr-9-en-3-one cyclic 1,2-ethanediyl acetal ; (5alpha,11beta,17beta)-11-[4-(dimethylamino)phenyl]-5,17-dihydroxy-17-(1-propynyl)-estr-9-en-3-one cyclic 1,2-ethanediyl acetal