Facile Regioselective Synthesis of 2-Methyl Furo [3,2-c][1] benzopyran-4-one 2-Methyl Furo[2,3-c] [1]benzopyran-4-one

The title compounds (7 &8) were obtained in excellent yields from 4-[2′-chloroprop-2′-enyloxy] [1] benzopyran-2-one (5) and 3-[2′-chloroprop-2-enyloxy][1]benzopyran-2-one (6) via [3,3] sigmatropic rearrangement and cyclisation of the intermediate chloroallylic enols with conc. H2SO4. The reaction was also studied in N,N-dimethyl aniline.