oxalyl dichloride in benzene 1.) 0 deg C, 0.5 h, 2.) 70 deg C, 1 h;

1: 83 percent / methanol / Irradiation 2: 1.) NaBH4, 2.) thionyl chloride / 1.) methanol, 0 deg C, 0.5 h, 2a.) from 0 deg C to 20 deg C, 3 h, 2b.) 65 deg C, 1 h 3: 1,8-diazabicyclo<5.4.0>undec-7-ene / CH2Cl2 / 3 h / 0 - 20 °C 4: 96 percent / base / H2O 5: 68 percent / oxalyl chloride / benzene / 1.) 0 deg C, 0.5 h, 2.) 70 deg C, 1 h View Scheme

1: 96 percent / base / H2O 2: 68 percent / oxalyl chloride / benzene / 1.) 0 deg C, 0.5 h, 2.) 70 deg C, 1 h View Scheme

1: 1,8-diazabicyclo<5.4.0>undec-7-ene / CH2Cl2 / 3 h / 0 - 20 °C 2: 96 percent / base / H2O 3: 68 percent / oxalyl chloride / benzene / 1.) 0 deg C, 0.5 h, 2.) 70 deg C, 1 h View Scheme