in pyridine T=0°C; Tosylation; 12 h;

With  sulfur trioxide pyridine complex; triethylamine in  dichloromethane; dimethyl sulfoxide T=0°C; 2 h;   

Multi-step reaction with 4 steps 1: 1.) DMSO, oxalyl chloride, 2.) Et3N / 1.) CH2Cl2, -60 deg C, 15 min, 2.) -60 deg C, 15 min, room temperature, 30 min2: 71 percent / benzene / 5 h / 70 °C3: 88 percent / lithium aluminium hydride / diethyl ether / 2 h / 0 °C4: 96 percent / m-chloroperoxybenzoic acid / CHCl3 / 2 h / -20 °C  

Multi-step reaction with 6 steps 1: 1.) DMSO, oxalyl chloride, 2.) Et3N / 1.) CH2Cl2, -60 deg C, 15 min, 2.) -60 deg C, 15 min, room temperature, 30 min2: 71 percent / benzene / 5 h / 70 °C3: 88 percent / lithium aluminium hydride / diethyl ether / 2 h / 0 °C4: 96 percent / m-chloroperoxybenzoic acid / CHCl3 / 2 h / -20 °C5: 69 percent / lithium aluminium hydride / tetrahydrofuran / 2 h / 0 °C6: 1.) dimethyl sulphide, N-chlorosuccinimide, 2.) triethylamine / 1.) toluene, ether, -20 deg C, 2 h, 2.) 30 min  

With  sodium tetrahydroborate in  methanol T=-40°C;   

Multi-step reaction with 2 steps 1: oxalyl chloride, DMSO, Et3N / CH2Cl2 2: 76 percent / tetrahydrofuran / 0.17 h / -35 °C  

Multi-step reaction with 3 steps 1: oxalyl chloride, DMSO, Et3N / CH2Cl2 2: 76 percent / tetrahydrofuran / 0.17 h / -35 °C3: 90 percent / PPTS / 3 h / Ambient temperature  

Multi-step reaction with 2 steps 1: 1) (COCl)2, DMSO; 2) Et3N2: 75 percent / benzene / 70 °C  

Multi-step reaction with 5 steps 1: 1.) DMSO, oxalyl chloride, 2.) Et3N / 1.) CH2Cl2, -60 deg C, 15 min, 2.) -60 deg C, 15 min, room temperature, 30 min2: 71 percent / benzene / 5 h / 70 °C3: 88 percent / lithium aluminium hydride / diethyl ether / 2 h / 0 °C4: 96 percent / m-chloroperoxybenzoic acid / CHCl3 / 2 h / -20 °C5: 69 percent / lithium aluminium hydride / tetrahydrofuran / 2 h / 0 °C  

Multi-step reaction with 7 steps 1: 1.) DMSO, oxalyl chloride, 2.) Et3N / 1.) CH2Cl2, -60 deg C, 15 min, 2.) -60 deg C, 15 min, room temperature, 30 min2: 71 percent / benzene / 5 h / 70 °C3: 88 percent / lithium aluminium hydride / diethyl ether / 2 h / 0 °C4: 96 percent / m-chloroperoxybenzoic acid / CHCl3 / 2 h / -20 °C5: 69 percent / lithium aluminium hydride / tetrahydrofuran / 2 h / 0 °C6: 1.) dimethyl sulphide, N-chlorosuccinimide, 2.) triethylamine / 1.) toluene, ether, -20 deg C, 2 h, 2.) 30 min7: 63 percent / benzene / 6 h / 80 °C