SEARCH Articles Figures Tables 1.4- Cyclohexadiene ring quinones Aromatic rings 1,4-cyclohexadienes Cyclohexadiene 1.3- , electrocyclic ring opening Cyclohexadiene photochemical ring opening Cyclohexadiene ring opening, thermal Cyclohexadiene, ring opening Cyclohexadienes electrocyclic ring closure Cyclohexadienes electrocyclic ring opening Cyclohexadienes photochemical ring opening