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)-halogen-(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 th epresence of a Lewis Acid 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.
本发明公开了一种制备光学活性(2S,3S)-别苯基去甲司他汀衍
生物(I)的工艺,包括在
钌膦络合物存在下不对称氢化4-苯基-2-卤代-
3-氧代丁酸酯(III),得到4-苯基-(2S)-卤代-(3R)-羟基
丁酸酯(IV)、在碱存在下使酯 (IV) 环氧化,得到 4-苯基-(2S,3R)-环氧
丁酸酯 (V)在
路易斯酸存在下,将酯 (V) 与三(低级烷基)
水杨酰
肼或(低级烷基)二
水杨酰
肼反应,得到 (3S)-azido-4-phenyl-(2S)-trisubstituted silyloxybutyric ester (VI)、将酯(VI)氢解为(2S,3S)-别苯基
山奈司他丁衍
生物(VII),保护化合物(VII)的
氨基,如果需要,在
氨基保护之前或之后对化合物进行
水解。可以安全地获得高光学纯度和高产率的化合物 (I)。