1,3-Dipolar cycloaddition of nitrile oxides to 1-phenylsulfonyl-1,3-butadienes: synthesis of 3-(4,5-dihydroisoxazol-5-yl)pyrroles

Novel heterocyclic compounds containing the 3-(4,5-dihydroisoxazol-5-yl)pyrrole ring system were synthesized in good yields (66–78%) by regioselective 1,3-dipolar cycloaddition of nitrile oxides to 1-phenylsulfonyl-1,3-dienes followed by Barton–Zard pyrrole annulation.