Collect. Czech. Chem. Commun. 1990, 55, 2481-2492

Cycloadditions of 2,5-dimethyl-3-furannitrile oxide to alkenes and alkynes

Eva Jedlovská, Lubor Fišera, Anna Balková, Jaroslav Kováč and Ladislav Štibrányi

Department of Organic Chemistry, Slovak Institute of Technology, 812 37 Bratislava


Regioselectivity of 1,3-dipolar cycloadditions of 2,5-dimethyl-3-furannitrile oxide (IIa) to alkenes or alkynes is described. Nitrile oxide IIa generated in situ reacts with monosubstituted alkenes or alkynes to give exclusively 5-substituted 3-(5-dimethyl-3 -furyl)-2-isoxazolines IV and isoxazoles V, 2,5-disubstituted alkenes sometimes afforded a mixture of regioisomeric isoxazolines. Reactivity of furannitrile oxides II and III in cycloadditions to ethene was studied by the MNDO method.