oxalyl dichloride; dimethyl sulfoxide; triethylamine in dichloromethane T=-78°C; 1 h;

(i) iBu2AlH, benzene, (ii) aq. HCl; Multistep reaction;

1: 1.) n-BuLi, TMEDA / 1.) ether, 50 gradC, 15 h.,2.) -78 gradC 2: 69 percent / pyridinium chlorochromate / CH2Cl2 View Scheme

1: 39 percent / Na / ethanol / 4 h / 60 °C 2: 82 percent / NaCl/H2O / dimethylsulfoxide / 19 h / 180 °C 3: 95 percent / LiAlH4 / diethyl ether / 1.) reflux, 1 h; 2.) RT, 10 h 4: 73 percent / oxalyl chloride, DMSO, NEt3 / CH2Cl2 / 1 h / -78 °C View Scheme

1: 82 percent / NaCl/H2O / dimethylsulfoxide / 19 h / 180 °C 2: 95 percent / LiAlH4 / diethyl ether / 1.) reflux, 1 h; 2.) RT, 10 h 3: 73 percent / oxalyl chloride, DMSO, NEt3 / CH2Cl2 / 1 h / -78 °C View Scheme

1: 95 percent / LiAlH4 / diethyl ether / 1.) reflux, 1 h; 2.) RT, 10 h 2: 73 percent / oxalyl chloride, DMSO, NEt3 / CH2Cl2 / 1 h / -78 °C View Scheme

1: 60 percent / PBr3 / 0.5 h / Ambient temperature 2: 39 percent / Na / ethanol / 4 h / 60 °C 3: 82 percent / NaCl/H2O / dimethylsulfoxide / 19 h / 180 °C 4: 95 percent / LiAlH4 / diethyl ether / 1.) reflux, 1 h; 2.) RT, 10 h 5: 73 percent / oxalyl chloride, DMSO, NEt3 / CH2Cl2 / 1 h / -78 °C View Scheme

1: 83 percent / p-toluenesulfonic acid, methanol / benzene / 1.5 h / Ambient temperature 3: 1.) TiCl3, Zu/Cu couple / 1.) DME, 1h, reflux, 2.) DME, 4h, reflux View Scheme