1: 80 percent / acetic acid, CrO3 / H2O / Ambient temperature 2: 83 percent / acetic acid, bromine / CHCl3 / 48 - 50 °C 3: 87 percent / ethanol / 1.5 h / Heating View Scheme

chromium(VI) oxide; acetic acid in water Ambient temperature;

1: pyridinium chlorochromate; sodium acetate / CH2Cl2 / 20 °C 2: phenyltrimethylammonium tribromide / tetrahydrofuran / 25 °C View Scheme