A new heterocyclic structure. The Benzopyrano[6,5,4-def] Benzopyran. (1,6-dioxapyrene)†‡

1,6-Dioxapyrene, the first unsubstituted dioxa-analogue of pyrene was synthesized in good yield from 2-carbomethoxy-6-methoxynaphthol[1,8-bc]pyran in a four-step reaction involving a peri-heterocyclisation. Its 1 H nmr spectral characteristics were compared with those of native pyrene