Isomerization of α-Pinene Oxide: Solvent Effects, Kinetics and Thermodynamics

Kinetics and thermodynamics of -pinene oxide isomerization was investigated both theoretically and experimentally in different solvents in the temperature range of 50-140 degrees C using different zeolites, iron modified zeolites, Fe-H-MCM-41 and micro-mesoporous ZSM-5 derived catalysts. The aim was to elucidate the effect of solvent basicity and polarity on the product distribution in this reaction giving as the main value-added products campholenic aldehyde and trans-carveol, which are used as fragrances and perfumes. A generic kinetic first order model was developed composed of both parallel and consecutive routes. A thermodynamic analysis showed that product selectivity is determined by kinetic control and not by thermodynamics. Formation of campholenic aldehyde was favored in non-polar solvents, whereas basic solvents promoted formation of trans-carveol independent on temperature. [GRAPHICS] .