Fluoro-substituted 3-cyano-2-methyl-benzo [b] furans and ethyl 2-methyl-benzo [b] furan-3- carboxylates are conveniently prepared in a single step in good yield by the microwave induced tandem intramolecular Wittig and Claisen rearrangement reactions of the corresponding [(aryloxyacetyl)(cyano) methylene] triphenylphosphorane and [(aryloxyacetyl)(ethoxycarbonyl) methylene] triphenylphosphoranes, respectively.