1: 1.) dimethyl sulfoxide, oxalyl chloride, 2.) triethylamine / 1.) dichloromethane, -60 deg C, 40 min, 2.) dichloromethane, from -60 deg C to RT, 60 min 2: 78 percent / KOH, iodobenzene diacetate / methanol / 3 h / 0 °C 3: 83 mg / 70 percent sodium bis(2-methoxyethoxy)aluminum hydride in toluene / benzene / Heating 4: 85 percent / p-toluenesulfonic acid (PTSA) monohydrate / tetrahydrofuran / 1.5 h / Heating View Scheme

1: (COCl)2, DMSO / CH2Cl2 / -60 - 20 °C 2: 78 percent / PhI(OAc)2, KOH / 0 °C 3: 83 percent / sodium bis(2-methoxyethoxy)aluminium (Red-Al) / benzene / Heating 4: 85 percent / p-TsOH / tetrahydrofuran / Heating View Scheme