Phenanthrenequinone reacts with morpholinocyclopentene piperidinocyclohexene, morp- holinocyclohexene and piperidinocyclopentene to give p- dioxine derivatives (Ila-d), while at room temperature only piperidinocyclopentene reacts with phenanthrenequinone to give (III). Chrysenequinone reacts with piperidinocyclopentene, morpholinocyclopentene, piperidinocyclo- hexene and morpholinocyclohexene to give (IVa-d) and not p-dioxine derivatives as reported before1