1: 98 percent / sulfuric acid / 18 h / Heating 2: 100 percent / LiAlH4 / diethyl ether / 18 h 3: 79 percent / 48percent aq. HBr / 0.25 h / Heating 4: 58 percent / Mg, iodine / diethyl ether / 24 h / Heating View Scheme