1: 5.5 g / pyridine 2: 54 percent / lithium aluminium chloride / diethyl ether / 20 h / 5 °C View Scheme

carbon tetrabromide; triphenylphosphine in dichloromethane 12 h;

1: 54 percent / N-bromosuccinimide, triphenylphosphine / benzene / 4 h 2: 1.) Mg, iodine / 1.) THF, 0.5 h, reflux; 2.) THF, -30 deg C to RT, RT, 1 h 3: 86 percent / cc. HCl / 12 h / Heating 4: 98 percent / potassium t-butoxide / diethyl ether / 0.5 h / 0 °C View Scheme

pyridinium chlorochromate