1: 1.) n-butyllithium, 2.) BF3*Et2O / 1.) THF, hexane, -78 deg C, 2.) THF, hexane 2: 40.1 percent / 4-(dimethylamino)pyridine, diisopropylethylamine / 8 h / 45 °C 3: 55.6 percent / LiAlH4 / tetrahydrofuran / 1 h / Heating 4: 92 percent / 2.) 0.5 N aq. sulfuric acid / acetonitrile / 16 h / 23 °C 5: 1.) dimsylsodium, sodium carbonate / 1.) 23 deg C, 20 min, 2.) 23 deg C, 4 h View Scheme