17alpha-Chlorethinyl-3-methoxyestra-1,3,5(10)-trien-17beta-ol 19-Norpregna-1,3,5(10)-trien-20-yn-17-ol, 21-chloro-3-methoxy-, (17alpha)- 974-76-5 Bdh 2398 Bdh-2398 NSC 64970