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.