dirhodium(II) tetrakis(perfluorobutyrate) in dichloromethane 0.5 h; Ambient temperature;

1: 1.) lithium diisopropylamide / 1.) THF, from -78 deg C to 0 deg C, 2 h, 2.) THF, -78 deg C, 3 h 2: oxalyl chloride / benzene / Ambient temperature 3: 0 - 20 °C 4: 56 percent / rhodium(II) perfluorobutyrate / CH2Cl2 / 0.5 h / Ambient temperature View Scheme

1: oxalyl chloride / benzene / Ambient temperature 2: 0 - 20 °C 3: 56 percent / rhodium(II) perfluorobutyrate / CH2Cl2 / 0.5 h / Ambient temperature View Scheme

potassium carbonate