Reaction of Mixed Carboxylic Anhydrides With Grignard Reagents. A Useful Method for the Preparation of Ketones

It was found that common ketones were prepared in good yields by the reaction of grignard reagents with mixed carboxylic anhydrides composed of o-substituted benzoic acids or pivalic acid and common carboxylic acids at −20 or −78°C. Further, it was established that a 1,4-diketone such as 2,5-dioxoundecane, a precursor of dihydrojasmone was synthesized in 71∼82% yields from levulinic acid by one step procedure without protecting its carbonyl group.