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.