Convenient Preparation of 2,7,8‐Trimethyl‐6‐hydroxychroman‐2‐carboxylic Acid (γ‐Trolox)

Abstract

The title chroman is useful in synthesis and as a water‐soluble analog of γ‐tocopherol, a member of the vitamin E family. This new synthesis of γ‐trolox proceeds via selective aromatic demethylation of Trolox, the more easily available 2,5,7,8‐tetramethyl homolog compound. This route is shorter than the previous synthesis, avoids the use of cyanide and methoxybutadiene, and requires no chromatography.

Keywords:

• aromatic demethylation
• decarbonylation
• tocopherol
• tocotrienol
• tocol
• Trolox

Acknowledgment

The author is grateful to Elias Couladouros (Athens, Greece) for helpful discussions regarding the preparation of chromans using the hetero‐Diels–Alder approach.