Isomerisation of 1,2-Epoxyalkanes: Effect of Different Solid Acids on Product Distribution,Mechanism and Kinetics

The rearrangement of epoxides over acidic and superacidic catalysts leads to several products with selectivity to the desired aldehyde depending upon the nature of the catalyst surface and the reaction conditions. This paper reports the studies with 1,2-epoxyoctane as a model compound, over several catalysts such as sulphated zirconia and zeolites, and dodecatungstophosphoric acid, phosphoric acid and ZnCl₂ supported on silica, clay and carbon. The typical products of rearrangement are aldehyde, allylic alcohols, furan and aldol. A mechanism for the formation of these species is given. H₃PO₄/SiO₂, dodecatungstophosphoric acid supported on K-10 clay and ZSM-5 were found to be efficient under different conditions. A kinetic model is presented. © 1997 SCI.