A facile conversion of ethoxydihydropyrans to 4-cyanoethylisoxazoles

The reaction of ethoxydihydropyrans 2, which were prepared from 2-methylene-1,3-dicarbonyl compounds 1 with ethyl vinyl ether, and hydroxylamine hydrochloride gave 4-cyanoethylisoxazoles 3 whose substituents at the 3 and 5 positions were transformed from substituent at the 2 position and the acyl group of 2 regioselectively.