| 摘要 |
PURPOSE:To obtain the titled compound in high selectivity without preparing by-products, by reacting a dicarboxylic acid with hydrogen by the use of a catalyst comprising palladium, chromium, and cobalt. CONSTITUTION:A dicarboxylic acid or its anhydrid is reacted with hydrogen in the presence of a catalyst containing palladium, chromium, and cobalt as essential components in the absence of a solvent or in a solvent such as a lactone, tetrahydrofuran, etc., to give a lactone. The catalyst used is usually obtained by preparing previously cobalt chromate from raw material compounds of a chromium component and a cobalt component, and adding a palladium component to it. An atomic ratio of palladium to chromium is 1/2,000-1/10, prefferably 1/1,1000-1/10,and an atomic ratio of cobalt to chromium is 1/10-10. maleic anhydride, succinic anhydride, etc., may be used as the dicabroxylic acid or its anhydride. |
