1: 1.) chromium trioxide, conc. sulfuric acid, 2.) 6 N HCl / 1.) water, acetone, room temperature, 18 h, 2.) glacial acetic acid, 70 deg C, 30 min. 2: 87 percent / 48percent HBr / acetic acid / 5 h / Heating View Scheme

chromium(VI) oxide; hydrogenchloride; sulfuric acid 1.) water, acetone, room temperature, 18 h, 2.) glacial acetic acid, 70 deg C, 30 min.; Yield given. Multistep reaction;