D,L‐α‐Tocopherol Synthesis Catalyzed by the Brønsted Acidic Ionic Liquids

Abstract

The synthesis of D,L‐α‐tocopherol from trimethylhydroquinone and isophytol using the Brønsted acidic SO₃H‐functionalized ionic liquids as catalysts was explored. The catalytic activities of the SO₃H‐functionalized ionic liquids were dependent on their anions. The yield of D,L‐α‐tocopherol also depended on the solvent, which was the reaction medium. A yield of 94.3% was obtained using the SO₃H‐functionalized ionic liquid with [BF₄ ⁻] anion as catalyst in propylene carbonate/heptane. The reaction mixture exhibited good biphasic behaviors, so that the produced D,L‐α‐tocopherol could be separated by decantation. The SO₃H‐functionalized ionic liquids could be reused after the removal of water.

Keywords:

• Brønsted acidic ionic liquid
• D‐L‐α‐tocopherol
• synthesis