1: 95 percent / activated MnO2 / CHCl3 / Ambient temperature 2: 65 percent / KH / benzene / 2 h / Ambient temperature 3: 90 percent / sodium hydrosulfite / methanol; H2O / 2 h / Heating 4: 90 percent / NaOCH3 / methanol / 0.67 h / 40 °C 5: 90 percent / Fremy's salt / methanol; H2O / 0.17 h / Ambient temperature 7: 80 percent / AlCl3 / CHCl3 / 1 h / Ambient temperature View Scheme