6,7-Dihydroacenaphtho[5,6-cd]pyran-1,3-dione is an intermediate in synthesizing 3,5,6-Tribromo-1,2-dihydroacenaphthylene (T771875), a derived from Acenaphthene (1,2-Dihydro Acenaphthylene) (D448330), which is a polycyclic aromatic hydrocarbons as carcinogenic agents.