Alkylation of 2(3H)-Furanones: Inter- versus Intra-Molecular

In this review, a survey on the behavior of 2(3H)-furanones as alkylating agents is systematized. It is obvious that the direction of the reaction was mainly dependent on the solvent used. Furanones reacted with AlCl3 in excess benzene, toluene, or anisole to give the corresponding butadienecarboxylic acids via an intermolecular alkylation mode. Carrying out the reaction in tetrachloroethane and nitrobenzene as solvents, the reactions may lead to intramolecular alkylation mode or fail to give any product and the unreacted furanones were isolated, depending upon the electron density on C-2 at the aryl group situated at position-3.