1: 65 percent / chloranil / xylene / 150 °C 2: 70 percent / di-isobutyl aluminiumhydride / tetrahydrofuran / 0 °C 3: 55 percent / DCC, dimethylaminopyridine / diethyl ether 4: 52 percent / AgO / dioxane; aq. HNO3 View Scheme