GENERATION OF NITRILE OXIDES VIA O-TRIBUTYLSTANNYL ALDOXIMES - APPLICATION TO THE SYNTHESIS OF ISOXAZOLINES AND ISOXAZOLES

Nitrile oxides were generated readily by the reaction of aldoximes 1, with tert-butyl hypochlorite and bis(tributyltin) oxide. The reaction proceeded efficiently under mild conditions, in which O-stannylated al doximes 2 are thought to be key intermediates. This reaction system wa s applicable to the one-pot syntheses of isoxazole derivatives 4 and 5 in the presence of dipolarophiles via a [3 + 2] cycloaddition.