Methyltrioxorhenium-catalyzed oxidation of pseudocumene for vitamin E synthesis: A study of solvent and ligand effects

Vitamin E is an essential food component of major economical relevance with important antioxidant properties and biological activity. The oxidation of pseudocumene to trimethyl-1,4-benzoquinone would be a key transformation in an alternative industrial production of α-tocopherol that is important for the antioxidant activity of vitamin E. The methyltrioxorhenium (MTO)-catalyzed oxidation of pseudocumene has been revisited to offer a more environmentally friendly, economically beneficial and milder approach to this important industrial product. It has been observed that by choosing the solvent and Lewis base additives (as ligands of MTO), both yield and chemoselectivity are considerably improved, allowing milder reaction conditions compared to previously reported protocols.

The MTO-catalyzed oxidation of pseudocumene for vitamin E synthesis was studied. Solvent and ligand influences were examined to optimize the reaction. Good yields and selectivities were obtained under relatively mild conditions.Figure optionsDownload high-quality image (55 K)Download as PowerPoint slideHighlights
► MTO catalyzes the oxidation of pseudocumene under mild conditions in good yields.
► Variations of different Lewis bases and solvents influence the product yield.
► Pseudocumene is a precursor for vitamin E synthesis.