Fujimoto–Belleau reaction

The Fujimoto–Belleau reaction is a chemical reaction that forms cyclic α-substituted α,β-unsaturated ketones from enol lactones. The reaction is named after the two chemists George I. Fujimoto and Bernard Belleau.

The reaction is a Grignard reaction, followed by a H-shift, an enol-keto tautomerisation and an Aldol addition reaction. The last step is an elimination (Aldol condensation) reaction with an E₁CB mechanism.