Effect of reaction conditions and kinetics of the isomerization of β-pinene epoxide to myrtanal in the presence of Fe/MCM-41 and Fe/SBA-15

Biomass valorization by isomerization of β-pinene epoxide was carried out over Fe supported on MCM-41 and SBA-15 materials. Several reaction conditions (kind of solvent, amount of catalyst, temperature, and time) were evaluated; myrtanal selectivity up to 85% was obtained (70 °C, 750 rpm, acetonitrile as solvent, 24 h) at a conversion of 99%. Apparently, solvent polarity affect myrtanal selectivity; the lowest conversions were obtained with the cyclic molecules THF and dioxane that have oxygen which pair electron free could be coordinated to the Fe center. Amount of catalyst increases availability of the active sites in the reaction medium which improves the conversion, nevertheless myrtanal selectivity did not change in the case of Fe/SBA-15. Yield to myrtanal increased as the amount of catalyst was raised. Estimated kinetic reaction constants for β-pinene epoxide isomerization over Fe/MCM-41 and Fe/SBA-15 were 1.6285 mol 0.4 h −0.4 g Fe −1 and 0.1404 mol 1.7 h −1.7 g Fe −1 , respectively. Apparently, β-pinene epoxide is more strongly adsorbed on Fe/SBA-15 than on Fe/MCM-41 catalyst. Fe/SBA-15 is a very attractive material for obtaining myrtanal with a high yield (up to 85%) and it is one of the best materials reported up to now for the synthesis of this aldehyde. Graphical abstract