Desogestrel InterMediates;18-methyl-11-methylene-4-estren-17-one;18-methyl-4-estrene-3,17-dione;13-ethyl-11-methylengon-4-ene;18-methyl-4-estren-3,17-dione;11-methylene-18a-homo-estr-4-en-17-one;18-Methylestr-4-en-3,17-dione;13-ethyl-11-methylenegona-4-en-17-one;Desogestrel EP IMpurity C;18a-homo-estr-4-en-3,17-dione;13b-Ethyl-11-methylenegon-4-en-17-one;13-Ethyl-11-methylene-gon-4-en-17-one;