申请人:YAMAKAWA CHEMICAL INDUSTRY CO., LTD.
公开号:EP0937705A2
公开(公告)日:1999-08-25
Disclosed are a novel process for preparing D-alloisoleucine and an improved process for epimerizing L-isoleucine to prepare D-alloisoleucine. In the former process, (2S, 3S)-tartaric acid derivative of formula I below; wherein R stands for a hydrogen atom, a C1-C3 lower alkyl group, lower alkoxy group, chlorine atom, bromine atom and nitro group; and "n" is a number of 0, 1 and 2; is combined with an epimer mixture of L-isoleucine and D-alloisoleucine in a reaction medium to form a complex of D-alloisoleucine and the compound of formula I. The precipitated complex is decomposed by putting it in an alcohol to isolate D-alloisoleucine. In the latter process, L-isoleucine is suspended in an inert solvent which does not substantially dissolve amino acids, and epimerized in the presence of C1-C5 saturated lower fatty acid and salicylaldehyde
本发明公开了一种制备 D-别异亮氨酸的新工艺,以及一种将 L-异亮氨酸外嵌化以制备 D-别异亮氨酸的改进工艺。在前一种工艺中,下式 I 的(2S,3S)-酒石酸衍生物;其中 R 代表氢原子、C1-C3 低级烷基、低级烷氧基、氯原子、溴原子和硝基;"n "是 0、1 和 2 的数字;在反应介质中与 L-异亮氨酸和 D-异亮氨酸的外嵌混合物结合,形成 D-异亮氨酸和式 I 化合物的复合物。将沉淀的复合物放入醇中分解,分离出 D-异亮氨酸。在后一种工艺中,将 L-异亮氨酸悬浮在一种基本上不溶解氨基酸的惰性溶剂中,并在 C1-C5 饱和低级脂肪酸和水杨醛的存在下进行表聚。