(1S-(1alpha,2alpha,6alpha,7alpha,8 alpha,9 beta,10 alpha,13alpha,14beta,17alpha))-21,21-Difluoro-2,4',5',6,7,8,9,10,11,12,13,14,15,16,20,21-hexadecahydro-10,13-dimethylspiro(17H-dicyclopropa(1,2:6,7)cyclopenta(a)phenanthrene-17,2'(3'H)-furan)-3(1H)-one 2',3alpha'-Tetrahydrofuran-2'-spiro-17-(6alpha,7alpha-difluoromethylene-1alpha,2alpha-methylene)-4-androsten-3-one 57129-44-9 6alpha,7alpha-Difluoromethylene-4',5'-dihydro-1alpha,2alpha-methylene-(17R)spiro(androst-4-ene-17,2'(3'H)-furan)-3-one MK 316 MK-316