Similar names: 19-Nor-17α-pregna-1,3,5(10)-trien-20-yn-17-ol, 3-(cyclopentyloxy)- (6CI,7CI,8CI); (17α)-3-(Cyclopentyloxy)-19-norpregna-1,3,5(10)-trien-20-yn-17-ol; 17-Ethynylestradiol cyclopentyl ether; 17α-Ethynylestradiol 3-cyclopentyl ether; 3-(Cyclopentyloxy)-19-nor-17α-pregna-1,3,5(10)-trien-20-yn-17-ol; 3-Cyclopentyloxy-17α-ethynyl-1,3,5(10)-estratrien-17-ol; 3-Cyclopentyloxy-17α-ethynylestra-1,3,5(10)-trien-17β-ol; EECPE; Eston; Estrovis; Estrovis 4000; Estrovister; Ethynylestradiol-3-cyclopentyl ether; Plestrovis; Qui-Lea; Quinestrol; W 3566