Total Synthesis of (R,R,R)‐γ‐Tocopherol through Cu‐Catalyzed Asymmetric 1,2‐Addition

Abstract Based on the asymmetric copper‐catalyzed 1,2‐addition of Grignard reagents to ketones, ( R,R,R )‐γ‐tocopherol has been synthesized in 36 % yield over 12 steps (longest linear sequence). The chiral center in the chroman ring was constructed with 73 % ee by the 1,2‐addition of a phytol‐derived Grignard reagent to an α‐bromo enone prepared from 2,3‐dimethylquinone.