(17α)-3-Ethoxy-19-norpregna-3,5-dien-20-yn-17-ol; Norethindrone 3-Ethyl Ether (8R,9S,10R,13S,14S,17R)-3-ethoxy-17-ethynyl-13-methyl-2,7,8,9,10,11,12,14,15,16-decahydro-1H-cyclopenta[a]phenanthren-17-ol; 3-ethoxy-19-nor-17α-pregna-3,5-dien-20-yn-17-ol
(17α)-3-Ethoxy-19-norpregna-3,5-dien-20-yn-17-ol; Norethindrone 3-Ethyl Ether (8R,9S,10R,13S,14S,17R)-3-ethoxy-17-ethynyl-13-methyl-2,7,8,9,10,11,12,14,15,16-decahydro-1H-cyclopenta[a]phenanthren-17-ol; 3-ethoxy-19-nor-17α-pregna-3,5-dien-20-yn-17-ol