1: 64 percent / Br2 / CHCl3 / 1.) 0-10 deg C, 2 h, 2.) refrigerator, 16 h 2: 93 percent / acetone; H2O / 10 h / Heating 3: 81 percent / dimethylformamide / 10 h / heating on a steam-bath 4: 94 percent / KOH, H2O / methanol / 7 h / Heating View Scheme