A new and stable nitroso-nitro-enamine reagent, providing a nitrile oxide 1,3-dipole, has been treated with dipolarophiles in the course of 1,3-dipolar cycloaddition reactions to give a large number of novel isoxazolyl-pyrroline derivatives. Surprisingly, instead of the expected 2-isoxazolyl-dihydropyrrole cycloadducts, dihydropyrrol-3-one oximes were isolated as

Substrate (I) reacts with a broad spectrum of unsaturated dipolarophiles to produce novel isoxazolyl‐pyrroline structures in generally low to moderate yields.