Potassium Fluoride-Promoted Reaction of (2-Chloro-2-nitroethenyl) benzenes with 1,3-Dicarbonyl Compounds. A General Synthesis of 6,6- Dimethyl-2-nitro-3-phenyl-3,5,6,7-tetrahydro-4(2H)benzofuranones and Some Analogs

A convenient procedure to prepare in good yields 6,6-dimethyl-2-nitro-3-phenyl-3,5,6,7-tetrahydro-4(2H)-benzofuranones starting from (2-chloro-2-nitroethenyl)benzenes and 5,5-dimethyl-1,3-cyclohexanedione in the presence of potassium fluoride is reported. This method also proved efficient with other 1,3-dicarbonyl compounds, and has been successfully extended to 1,3-cyclohexanedione, 2,5-pentanedione, dibenzoylmethane and ethyl acetoacetate.