The dipolar cycloaddition reactivity of N-(1-naphthy1)-1,4- benzoquinoneimine
N-oxide and N-phenyl-1,4- naphthoquinoneimine Noxide
are investigated, The latter gives the expected adducts with common
dipolarophiles such as acrylonitryle, methyl methacrylate, dimethylacetylene
dicarboxylate and N-phenylmaleimide. The reactivity of
the former nitrone is found to be minimal. It undergoes, however, an
anomalous reaction with DMAD to give, after rearrangement, 1-(4-hydroxypheny1) 3, 3-dicarboxymethylbenzooxindole