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    • 95. 发明授权
    • Chemical process for fluorinating a tertiary carbon atom in the steroid
nucleus
    • 用于氟化类固醇核中叔碳原子的化学方法
    • US4284558A
    • 1981-08-18
    • US775879
    • 1977-03-09
    • Derek H. R. BartonRobert H. Hesse
    • Derek H. R. BartonRobert H. Hesse
    • C07B31/00C07B39/00C07C17/00C07C17/10C07C19/08C07C19/10C07C19/12C07C23/20C07C67/00C07J1/00C07J5/00C07J7/00C07J9/00C07J41/00C07J53/00C07J75/00
    • C07J53/00C07B39/00C07C17/10C07J1/0011C07J1/0025C07J41/005C07J5/0076C07J7/002C07J7/0055C07J9/00
    • Saturated organic compounds containing a hydrogen atom bound to a tertiary carbon atom may be electrophilically fluorinated by reaction with an electrophilic fluorinating agent such as molecular fluorine or trifluoromethyl hypofluorite under conditions whereby the formation of free fluorine radicals is suppressed, e.g. by the presence of a free radical inhibitor such as oxygen or nitrobenzene, the reactants being substantially homogeneously dispersed in a liquid medium, e.g. a solvent medium such as fluorotrichloromethane or chloroform/fluorotrichloromethane, so that the said hydrogen atom is electrophilically replaced by a fluorine atom. The fluorination is highly selective and, in the case of complex substrates such as saturated steroids which contain a number of tertiary C--H bonds, may be substantially completely confined to replacement of the hydrogen atom at the tertiary carbon atom which has the highest electron density about the C--H bond. The electron density and thus the direction of the fluorination may be controlled by appropriate selection of substituent groupings in the substrate molecule.Novel 14.alpha.-fluorosteroids are also disclosed, including compounds having valuable androgenic or progestational activity and useful synthetic intermediates.
    • 含有与叔碳原子结合的氢原子的饱和有机化合物可以通过与亲电氟化剂如分子氟或三氟甲基次氟酸荧光反应,在抑制游离氟自由基形成的条件下进行亲电氟化。 通过存在自由基抑制剂如氧或硝基苯,反应物基本均匀地分散在液体介质中,例如, 溶剂介质如氟三氯甲烷或氯仿/氟三氯甲烷,使所述氢原子被氟原子亲电取代。 氟化是高度选择性的,并且在复杂的底物例如含有多个叔CH键的饱和类固醇的情况下,可以基本上完​​全限制于在具有最高电子密度的叔碳原子上的氢原子的取代 CH键。 可以通过适当选择底物分子中的取代基组来控制电子密度以及氟化方向。 还公开了新的14种α-氟甾类,包括具有有价值的雄激素或促孕活性的化合物和有用的合成中间体。