1: 98 percent / Fe2(CO)9 / benzene / 4 h / Heating 2: 100 percent / 2 M aq. HClO4 / CH2Cl2 / 5 h / Ambient temperature 3: 75 percent / diethyl ether / 0.25 h / Ambient temperature 4: 15 percent / AgO, 6 M aq. HNO3 / dioxane / 0.25 h / Ambient temperature 5: 56 percent / H2SO4 / ethanol / 0.5 h / Heating View Scheme