thionyl chloride in diethyl ether 0.25 h; Heating;

1: toluene-4-sulfonic acid / 72 h / |Inert atmosphere; |Heating 2: N,N-dimethyl-formamide; oxalyl dichloride / dichloromethane / 1 h / 20 °C / |Inert atmosphere View Scheme

1: 94 percent / Et3N / benzene / 2 h 2: 84 percent / LiCl; NaBH4 / tetrahydrofuran; ethanol / 16 h / 20 °C 3: 70 percent / PPh3; DEAD; diphenylphosphoryl azide / tetrahydrofuran / 24 h / 20 °C 4: tristrimethylsilane; AIBN / benzene / 5 h / Heating 5: 73.6 mg / NaCNBH3 / acetonitrile / 0.25 h / 20 °C 6: 83 percent / NH3; Na / tetrahydrofuran / 0.2 h / -50 °C View Scheme