2-Cyano-6-(trifluoromethyl)-4H-pyran-4-one: A novel versatile CF3-containing building block

A highly electrophilic pyrone, 2-cyano-6-(trifluoromethyl)-4H-pyran-4-one, was synthesized. The reactions of this cyanopyrone with N-nucleophiles can proceed with or without substitution of the cyano group to give a wide range of novel trifluoromethylated compounds. An oxindole derivative was synthesized from a phenylhydrazide using unusual (acidic) conditions.