Reactions of 5-aryl-furan-2,3-diones with acylmethylenetriphenylphosphoranes: synthesis and biological activity of 3(2H)-furanone derivatives.

The Wittig reaction of 5-aryl-furan-2,3-diones 1 with acylmethylenetriphenylphosphoranes 2 conducted by heating under reflux in benzene solutions, proceeded regiospecifically to afford 2-acylmethylene-5-aryl-3(2H)-furanones 5 in good yields. When the starting compounds 1 and 2 were allowed to react at room temperature, the stable intermediate 5-aryl-2-hydroxy-2-triphenylphosphoranylidenemethyl-3(2H)-furanone s 15 were yielded. The latter adducts underwent triphenylphosphine oxide elimination on heating to form the same olefins 5. The structural assignments of the synthesized compounds were made on the basis of their spectral data and X-ray analysis for 5a. Some of the compounds obtained exhibit antimicrobial activity and one compound of the 3(2H)-furanone series exhibited anticonvulsant activity.