A Convenient access to (All-rac)-α-tocopherol acetate from linalool and dihydromyrcene

Article abstract of DOI:10.1246/bcsj.82.829

Refluxing trimethylhydroquinone 2 in 10:1 dodecane/CH²Cl ² with linalool 3b (two-fold excess) and camphorsulfonic acid, then treating the crude condensation product (consisting of a mixture of the chromanols 1b and 1c, alongside the tricyclic compounds 9 and 10) sequentially with Ac²O and m-CPBA afforded, after removal by column chromatography of the 9/10 acetates, a mixture of the regioisomeric epoxides 1jOAc and 1kOAc (ratio 9:1, total 60%). Treatment of this mixture with Al(O-i-Pr)³ followed by CuI-catalysed Wurtz coupling of the acetates of the resulting allylic alcohols with citronellylmagnesium chloride 12a, and finally hydrogenation then provided the title acetate (overall 46% from 2).