Hydrogenation of Sorbic Acid Catalyzed with Cyanocobalt(II) Complexes

Abstract

The hydrogenation of sorbic acid catalyzed with cyanocobalt(II) complexes in the range of the CN/Co ratio from 2 to 8 has been studied at 30° C and 1 atm. Main products obtained were 2-hexenoic acid at CN/Co> 5 and 3-hexenoic acid at CN/Co < 4. Addition of potassium chloride to the complex increased the rate of hydrogenation remarkably. Analysis of the products -showed- that in the range of CN/Co from 2 to 4, 2-hexenoic acid was obtained in nearly the same amount as 3-hexenoic acid. However, for CN/Co> 4, the selectivity for 2- hexenoic acid increased with an increase in CN/Co ratio. Potassium hydroxide showed a different effect on the hydrogenation from the effect by potassium chloride. In this case, composition of the products remained constant in the range of CN/Co from 2 to 8. The effect of various neutral salts and bases on the hydrogenation has been studied.