1: 76 percent / KOH, tetrabutylammonium iodide / CH2Cl2 / 16 h / Ambient temperature 2: 65 percent / 45percent HBr / 0.5 h / Heating View Scheme

1: 1.) BuLi / 1.) THF, hexane, -70 deg C, 10 min, 2.) THF, hexane, -70 deg C, 5 h 2: 70 percent / 0.25 N aq. HCl / 3 h / Ambient temperature 3: 47 percent / 48percent aq. HBr / 0.25 h / Heating View Scheme