13563-60-5 17.alpha.-Vinyl-5(10)-estrene-17.beta.-ol-3-one 19-Nor-17.alpha.-pregna-5(10),20-dien-3-one, 17-hydroxy- 19-Norpregna-5(10),20-dien-3-one, 17-hydroxy-, (17.alpha.)- NSC72160 Norgesterone Vinylestrenolone