Rare earth triflate catalysts in the synthesis of Vitamin E and its derivatives

Vitamin E is known as the most important fat-soluble antioxidant in biological systems. The scale for commercially produced (all-rac)-alpha-tocopherol reaches over 25,000 tonnes per year. The known processes for the synthesis of a-tocopherol suffer from disadvantages like formation of by-products and waste-water problem. To overcome these drawbacks, new types of catalysts have been developed. These are rare earth metal triflates, e.g. Bi(OTf)(3), Ga(OTf)(3), Tm(OTf)(3) Or Hf(OTf)(4). This new approach to Vitamin E or derivatives thereof has several advantages, based on high yields (above 94%) and selectivities. (c) 2006 Elsevier B.V. All rights reserved.