申请人:Takasago International Corporation
公开号:EP0369691A2
公开(公告)日:1990-05-23
For preparing an optically active 3-hydroxybutanoic acid of formula:
wherein R¹ represents a protective group of carboxylic acid, and R² represents hydrogen, C1-4 alkyl which may be substituted with halogen, C1-4 alkoxy or a phenyl or benxyloxy which may each be substituted with a C1-4 alkyl or alkoxy;
a 3-oxobutanoic acid ester of formula:
wherein R¹ and R² are as defined above,
preferably in a halogenated hydrocarbon solvent under H₂ pressure of 10-150 kg/cm² at 15-100°C for 10-40 hours, is asymmetrically hydrogenated in the presence as a catalyst of a ruthenium-optically active phosphine complex, preferably a 'BINAP' tertiary phosphine complex.
The compound (I) can be used for synthesizing in 5 steps a 4-acetoxyazetidin-2-one derivative, a useful intermediate for obtaining penem antibiotics.
The synthesis of (I) is carried out economically from (II) which is easily prepared from an aceto-acetic ester.
用于制备具有光学活性的式 3-羟基丁酸:
其中 R¹ 代表羧酸的保护基团,R² 代表氢、可被卤素取代的 C1-4 烷基、C1-4 烷氧基或可分别被 C1-4 烷基或烷氧基取代的苯基或苯氧基;
式中的 3-氧代丁酸酯:
其中 R¹ 和 R² 如上定义、
最好是在卤代烃溶剂中,在 10-150 kg/cm² 的 H₂压力下,15-100°C,10-40 小时,在钌-光活性膦络合物(最好是 "BINAP "叔膦络合物)作为催化剂存在下进行不对称氢化。
化合物(I)可通过 5 个步骤合成 4-乙酰氧基氮杂环丁-2-酮衍生物,该衍生物是获得青霉烯抗生素的有用中间体。
(I)的合成可以经济地从(II)中进行,而(II)很容易从乙酰乙酸酯中制备出来。