A process for preparing an optically active (2S,3S)-allophenylnorstatin derivative (I) is disclosed, comprising asymmetrically hydrogenating a 4-phenyl-2-halogeno-3-oxobutyric ester (III) in the presence of a ruthenium-phosphine complex to obtain a 4-phenyl-(2S)-halogeno-(3R)-hydroxybutyric ester (IV), epoxidizing the ester (IV) in the presence of a base to obtain a 4-phenyl-(2S,3R)-epoxybutyric ester (V), reacting the ester (V) with a tri(lower alkyl)silylazide or a (lower alkyl)diarylsilylazide in the presence of a Lewis to obtain a (3S)-azido-4-phenyl-(2S)-trisubstituted silyloxybutyric ester (VI), hydrogenolyzing the ester (VI) into a (2S,3S)-allophenylnorstatin derivative (VII), protecting the amino group of the compound (VII), and, if desired, hydrolyzing the compound before or after the amino group protection. Compounds (I) can be obtained at high optical purity safely and in good yield.
本发明揭示了一种制备光学活性的(2S,3S)-异苯基诺斯他汀衍
生物(I)的方法,包括在
钌-膦配合物的存在下,对4-苯基-2-卤代-3-酮
丁酸酯(III)进行不对称氢化反应,从而得到4-苯基-(2S)-卤代-(3R)-羟基
丁酸酯(IV),在碱的存在下将酯(IV)环氧化,得到4-苯基-(2S,3R)-环氧
丁酸酯(V),在Lewis的存在下,将酯(V)与三(较低烷基)
硅基
氮化物或(较低烷基)二芳基
硅基
氮化物反应,得到(3S)-偶氮-4-苯基-(2S)-三取代
硅氧基
丁酸酯(VI),将酯(VI)氢解成(2S,3S)-异苯基诺斯他汀衍
生物(VII),保护化合物(VII)的
氨基团,如有需要,在
氨基团保护之前或之后
水解化合物。化合物(I)可以安全地高光学纯度地获得,并且收率良好。