Nitrone Cycloadditions to 1,2-Diphenylcyclopropenes and Subsequent Transformations of the Isoxazolidine Cycloadducts

1,3-Dipolar cycloaddition of C-aryl,N-aryl (or N-methyl) nitrones with a number of 1,2-diphenylcyclopropenes substituted at the C3 position occurs with the formation of expected “normal” cycloadducts (with N-methylnitrones) and products of their subsequent transformations. Among them are corresponding α-acetophenyl aziridines and tetra (or penta) -arylpyrroles. Aziridines and the normal cycloadducts can be also thermally converted to such arylpyrroles with moderate to good yields. Substitution at the C3 position of cyclopropenes by an electron acceptor group decreases the reactivity of cyclopropenes.