sheet: Not available Spectra: Check on SDBS . Add Spectra ( Help ). From Wikipedia Quinestrol (ethinyl estradiol 3-cyclopentyl ether) is synthetic estrogen used in hormone replacement therapy , and occasionally to treat breast cancer and prostate cancer . Read more... Edit at Wikipedia... Other names (17beta)-3-(Cyclopentyloxy)-17-ethynylestra-1,3,5(10)-trien-17-ol; 17a-Ethinylestradiol 3-Cyclopentyl Ether; (17Alpha)-3-(cyclopentyloxy)-19-norpregna-1,3,5(10)-trien-20-yn-17-ol; 3-(Cyclopentyloxy)-19-nor-17a-pregna-1,3,5(10)-trien-20-yn-17-ol; (17Beta)-3-(cyclopentyloxy)-17-ethynyl-estra-1,3,5(10)-trien-17-ol