The progestins allylestrenol (3-deketo-17α-allyl-19-NT) and lynestrenol (3-deketo-17α-ethynyl-19-NT) are also closely related to ethylestrenol, differing only by the C17α substitution.
ðə pɹoʊdʒˈɛstɪnz ˈælaɪlˌɛstɹənˌɑːl θɹˈiːdɛkˈiːɾoʊ sˈɛvəntˌiːn ˈælfəˈælaɪl nˈaɪntiːnˌɛntˈiː ænd lˈaɪnɪstɹˌɛnɑːl θɹˈiːdɛkˈiːɾoʊ sˈɛvəntˌiːn ˈælfəˈɛθɪnˌaɪl nˈaɪntiːnˌɛntˈiː ɑːɹ ˈɔːlsoʊ klˈoʊsli ɹᵻlˈeɪɾᵻd tʊ ˈɛθaɪlstɹˌɛnɑːl, dˈɪfɚɹɪŋ ˈoʊnli baɪ ðə sˈiː sˈɛvəntˌiːn ˈælfə sˌʌbstɪtˈuːʃən.