chromium(VI) oxide in pyridine T=20°C; 12 h;

1: 82 percent / 50percent aq. KOH / acetone / 1 h / 20 °C 2: 95 percent / Br2 / 1,2-dichloro-ethane / 1 h / Irradiation 3: 73 percent / H2O / dioxane / 4 h / Heating 4: 70 percent / CrO3 / pyridine / 12 h / 20 °C View Scheme

1: 95 percent / Br2 / 1,2-dichloro-ethane / 1 h / Irradiation 2: 73 percent / H2O / dioxane / 4 h / Heating 3: 70 percent / CrO3 / pyridine / 12 h / 20 °C View Scheme

1: 73 percent / H2O / dioxane / 4 h / Heating 2: 70 percent / CrO3 / pyridine / 12 h / 20 °C View Scheme

1: 70 percent / conc. HCl / acetic acid / 2 h / 80 °C 2: 82 percent / 50percent aq. KOH / acetone / 1 h / 20 °C 3: 95 percent / Br2 / 1,2-dichloro-ethane / 1 h / Irradiation 4: 73 percent / H2O / dioxane / 4 h / Heating 5: 70 percent / CrO3 / pyridine / 12 h / 20 °C View Scheme

(NH4)2CO3 T=175 - 180°C; 7 h;