Cushman Darby & Cushman IP Group of Pillsbury Madison & Sutro LLP
Steroid derivatives
 To provide novel steroid derivatives having an antitumor action which can be synthesized efficiently and stereoselectively by means of synthetic organic chemistry. A steroid derivative represented by the formula: ##STR1## wherein R is an alkyl group having 1 to 13 carbon atoms, A is a hydroxyl group or a group easily hydrolyzable to a hydroxyl group, X and Y together form an oxo group or an alkylenedioxy group having 2 or 3 carbon atoms, X is a hydroxyl group, an alkoxy group having 1 to 5 carbon atoms or a group easily hydrolyzable to a hydroxyl group, Y is a hydrogen atom or an alkoxy group having 1 to 5 carbon atoms, with the proviso that when X is a hydroxyl group or a group easily hydrolyzable to a hydroxyl group, Y is a hydrogen atom, and when X is an alkoxy group having 1 to 5 carbon atoms, Y is an alkoxy group having 1 to 5 carbon atoms, or a salt thereof. 
Taisho Pharmaceutical Co., Ltd.
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C07J C07J C07J C07J
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Katsuo Hidemichi Tatsuhiko Hisaya Yasuji Chihiro
Hatayama Mitome Sano Wada Yamada Yokoo