17-alpha-Chloroethynyl-3,17-beta-dimethoxy-oestra-1,3,5(10)-triene 19-Nor-17-alpha-pregna-1,3,5(10)-trien-20-yne, 21-chloro-3,17-dimethoxy- 19-Nor-17alpha-pregna-1,3,5(10)-trien-20-yne, 21-chloro-3,17-dimethoxy- (8CI) 19-Norpregna-1,3,5(10)-trien-20-yne, 21-chloro-3,17-dimethoxy-, (17-alpha)- 19-Norpregna-1,3,5(10)-trien-20-yne, 21-chloro-3,17-dimethoxy-, (17alpha)- (9CI) 21-Chloro-3,17-dimethoxy-19-nor-17-alpha-pregn-1,3,5(10)-trien-20-yne 7548-44-9 BDH 2700 NSC 84053