1: 79 percent / CrO3-pyridine / CH2Cl2 2: 2.) n-butyllithium, t-BuOK / 1.) THF, -78 deg C, 2.) t-BuOH 4: 100 percent / m-chloroperbenzoic acid / CH2Cl2 / Ambient temperature 5: 93 percent / 2 h / 120 °C 6: K2CO3 / methanol / Ambient temperature 7: SOCl2 / benzene 8: dimethylsulfoxide / 43 °C 9: 1.) t-BuOK, 2.) oxalic acid / 1.) THF/Me2SO, -12 deg C, 2.) THF/H2O, reflux 10: 100 percent / perfluoroacetic acid, Na2HPO4 / CH2Cl2 / Ambient temperature 11: 100 percent / KMnO4 / acetone; H2O / Ambient temperature 12: 1.) (PhO)2PON3, NEt3, 2.) H2O / 1.) C6H6, reflux, 1 h, 2.) reflux, 0.5 h 13: 1.) acetic anhydride, 2.) K2CO3 / 1.) 120-125 deg C, 2 h, 2.) CH3OH, room temperature, 1.5 h 14: 100 percent / MnO2 / CHCl3 / Ambient temperature 15: 46 percent / tetrahydrofuran; hexamethylphosphoric acid triamide / -78 °C 16: 95 percent / activated MnO2 / CHCl3 / Ambient temperature 17: 65 percent / KH / benzene / 2 h / Ambient temperature 18: 90 percent / sodium hydrosulfite / methanol; H2O / 2 h / Heating 19: 90 percent / NaOCH3 / methanol / 0.67 h / 40 °C 20: 90 percent / Fremy's salt / methanol; H2O / 0.17 h / Ambient temperature 22: 80 percent / AlCl3 / CHCl3 / 1 h / Ambient temperature View Scheme