Catalytic isomerisation of α-pinene oxide to campholenic aldehyde using silica-supported zinc triflate catalysts I.: Kinetic and thermodynamic studies

Three silica- supported zinc triflate (Zn(CF3SO3)(2)) catalysts have been studied in a batch reactor for performing isomerisation reaction of alpha-pinene oxide to campholenic aldehyde. Reaction order was evaluated from the obtained experimental data by using an integral method of data analysis. Reaction rate constants were obtained at different temperatures and activation energies using each catalyst determined. Different catalyst loadings and supports were tested in this study: 0.05 mmol/g Zn-triflate/K60 (Catalyst 1), 0.01 mmol/g Zn-triflate/K100 (Catalyst 2) and 0.05 mmol/g Zn-triflate/HMS24 (Catalyst 3). Various methods for determining heat of reaction were used in order to calculate thermodynamic parameters. Heat of alpha-pinene oxide to campholenic aldehyde isomerisation reaction was estimated as -73.2 kJ/mol. (C) 2006 Elsevier B.V. All rights reserved.