1: 5 percent / benzene / 18 h / 240 °C / sealed tube 2: 63 percent / BF3*Et2O / CH2Cl2 / 2 h / Ambient temperature 3: 1 percent Chromat. / W-7 Raney-nickel / hexane; ethanol / 3 h / Heating View Scheme

With  oxalyl dichloride in  dichloromethane; dimethyl sulfoxide  

 in  benzene T=240°C; 18 h;  sealed tube;