The kinetics of methyl sorbate hydrogenation Original Research Article

Methyl trans-2-hexenoate was prepared with a two-step synthesis from trans,trans-2,4-hexadienoic acid (sorbic acid). The first step was the methanol esterification of sorbic acid catalyzed with sulfuric acid. The second step was a catalytic hydrogenation of the resulting methylester using metallic catalysts based on Pt, Pd, Rh and Ni carried on an activated carbon and γ-alumina. During the hydrogenation reactions, in all cases, monoolefinic methyl trans-2-hexenoate was produced as the main reaction intermediate. Varied isomers of methyl 3- and 4-hexenoates resulted from the reactions as the side intermediates. The resulting intermediates further hydrogenated to a common product, methyl hexanoate. Palladium was the most apposite catalyst, due to its high activity and significant selectivity to the production of methyl trans-2-hexenoate. At the end, the raw intermediate was rectificated under the atmospheric pressure.