The kinetics of stereoselective hydrogenation of (−)-menthone and (+)-isomenthone mixture using nickel catalysts Original Research Article

The kinetics of the catalytic hydrogenation of optically active mixture of (−)-menthone and (+)-isomenthone was studied. Raney nickel and Ni/SiO2 were used as catalysts. Catalysts modified with tartaric acid (TA) were tested as well. Various isomers were produced in these reactions, especially (+)-neomenthol and (+)-neoisomenthol. Small amount of (−)-menthol was produced, the yield of (−)-isomenthol was minimal. An isomerization of (−)-menthone and (+)-isomenthone occurred during these reactions. Isomerizations among individual menthol isomers were not detectable under the given reaction conditions. Based on the acquired experimental data, a kinetic model of the Langmuir–Hinshelwood type was created. This model was further continuously adjusted and simplified as to describe the experimental data and acquire optimal kinetic model parameters.