3-Hemisuccinates (3-(3-carboxypropanoates)) XI-XV, derived from cholesterol (I), (20R)-3β-hydroxy-21-norchola-5,22-dien-24 20-olide (II), estrone (III), (20E)-21-methoxycarbonyl-3β-hydroxypregna-5,20-diene (IV) and digitoxigenine (V), were prepared via the mixed succinates of the alcohols I-V and trichloroethanol (3-[4-(2,2,2-trichloroethoxy)-4-oxobutanoates] VI-X). The usual acylation of II and IV with succinic anhydride in pyridine failed.
3-羟基琥珀酸酯(3-(3-羧基丙酸酯)) XI-XV,源自胆固醇(I),(20R)-3β-羟基-21-去甲胆甾-5,22-二烯-24 20-酮(II),雌二醇(III),(20E)-21-甲氧羰基-3β-羟基孕烯-5,20-二烯(IV)和地高辛(V),通过醇类I-V和三氯乙醇(3-[4-(2,2,2-三氯乙氧基)-4-氧代丁酸酯] VI-X)的混合琥珀酸酯制备而成。在吡啶中用琥珀酸酐对II和IV进行常规酰化失败。