conditions using powdered sodium hydroxide and benzyltriethylammonium chloride as catalyst in dimethylsulfoxide to afford mixtures of a methylenechromane and a methylchromene via favored 6-exo-dig and 6-endo-dig processes, respectively. Several of the chromenes rearranged into benzofuranone derivativesduring column chromatography on alumina and the formation of these is rationalized. phase-transfer