Studies on the Isomerization of 2,4-Dinitrophenylhydrazones of Some Aliphatic α-Keto Acids and the Preparation of Their Geometrical Isomers
作者:Hirohiko Katsuki、Chizuko Tanegashima、Masanobu Tokushige、Shozo Tanaka
DOI:10.1246/bcsj.45.813
日期:1972.3
of some aliphatic α-keto acids takes place in water and some organic solvents by the catalysis of hydrogen ions. Trans isomer is more stable than cis isomer for lower keto acids and the reverse is the case for higher keto acids. The fraction of cis isomer in isomeric mixture at equilibrium in organic solvents such as ethyl acetate and ethyl ether, saturated with 6N hydrochloric acid, was larger than
一些脂肪族α-酮酸的2,4-二硝基苯腙的顺反异构化反应在水和一些有机溶剂中通过氢离子的催化发生。对于较低的酮酸,反式异构体比顺式异构体更稳定,而对于较高的酮酸则相反。在用6N盐酸饱和的有机溶剂如乙酸乙酯和乙醚中平衡的异构体混合物中顺式异构体的比例大于在水溶液中的比例。这两种异构体可以通过它们在 1N 碳酸钠中溶解度特性的差异进行分离,除了一些带有叔或季 β-碳的酮酸。当用通常的方法测量时,发现一些腙异构体对的熔点是相同的。