5-Nitro[2.2]paracyclophanepyran-6-one-building block for the synthesis of [2.2]paracyclophanes containing condensed benzofuran subunits

The 5-nitro[2.2]paracyclophanepyran-6-one 2 has been synthesized. DBN treatment of the Diels-Alder cycloadducts of 2 followed by DDQ oxidation unexpectedly led to [2.2]paracyclophanes containing a condensed benzofuran subunit.