A simplest member of the class of chromene in which the heterocyclic pyran ring has a double bond between positions 2 and 3. ChEBI: 4H-chromene is a simplest member of the class of chromene in which the heterocyclic pyran ring has a double bond between positions 2 and 3. It is a chromene and an organic heterobicyclic compound. It is a tautomer of a 2H-chromene.