5-Isoxazolylhydrazines. Reduction of 5-isoxazolones to isoxazoles

5-Isoxazolylhydrazines III were obtained from 5-isoxazolones I, via the 5-haloisoxazoles II. The decomposition of the tosyl derivatives of III results in unambigous syntheses of 3,4-disubstituted isoxazoles.