1: CH2Cl2 / Ambient temperature 2: 81 percent / tetrahydrofuran / 15 h / Ambient temperature 3: 1.) hydriodic acid; 2.) hydriodic acid / 1.) glacial acetic acid, reflux, 2 h; 2.) acetic acid, reflux, 7 h 4: 1.) potassium carbonate; 2.) pyridine, dimethylaminopyridine / 1.) DMSO, acetone, r.t., 2 h 5: 75 percent / N-bromosuccinimide, dibenzoylperoxide / CCl4 / 6 h / Heating 6: 1.) sodium borohydride, diphenyl diselenide; 2.) 30percent H2O2 / 1.) ethanol, THF, 2.5 h, reflux; 2.) THF, ethanol, 3 h, 0 deg C View Scheme

With  thionyl chloride; N,N-dimethyl-formamide in  toluene T=60°C; 1 h;   

Multi-step reaction with 5 steps 1: CH2Cl2 / 2 h / Ambient temperature2: 82 percent / SOCl2 / 0.5 h / Ambient temperature3: 1) 1.6 M BuLi / 1) THF, hexane, -78 deg C, 1 h, 2) -45 deg C, 1.5 h4: 70 percent / 2 M aq. HCl / 1 h / Heating5: SOCl2, DMF / toluene / 1 h / 60 °C  

Multi-step reaction with 2 steps 1: 70 percent / 2 M aq. HCl / 1 h / Heating2: SOCl2, DMF / toluene / 1 h / 60 °C  

Multi-step reaction with 2 steps 1: CH2Cl2 / Ambient temperature2: 81 percent / tetrahydrofuran / 15 h / Ambient temperature  

Multi-step reaction with 3 steps 1: CH2Cl2 / Ambient temperature2: 81 percent / tetrahydrofuran / 15 h / Ambient temperature3: 1.) hydriodic acid; 2.) hydriodic acid / 1.) glacial acetic acid, reflux, 2 h; 2.) acetic acid, reflux, 7 h