manganese(IV) oxide in dichloromethane Ambient temperature;

in water T=20°C; 24 h;

1: With acetic acid in methanol T=20°C; 1 h; 2: With acetic anhydride Heating;

1: 83 percent / toluene / Heating 2: 91 percent / NaBH4 / methanol / 2 h / Heating 3: 65 percent / MnO2 / CH2Cl2 / Ambient temperature View Scheme

1.1: hydrogenchloride; sodium nitrite / water / 0.5 h / 0 - 5 °C 1.2: 0 - 20 °C 2.1: CuSO4‵5H2O; sodium L-ascorbate / water; tert-butyl alcohol / 20 °C / Darkness 3.1: 1-hydroxy-3H-benz[d][1,2]iodoxole-1,3-dione / dimethyl sulfoxide / 20 °C View Scheme

1: 91 percent / NaBH4 / methanol / 2 h / Heating 2: 65 percent / MnO2 / CH2Cl2 / Ambient temperature View Scheme