triethyloxonium tetra-fluoroborate in dichloromethane Ambient temperature;

1: 1.) butyllithium / 1.) THF, hexane, -30 deg C, 30 min, 2.) -30 deg C, 30 min 2: 93 percent / thionyl chloride, pyridine / 0.5 h / 0 °C 3: 90 percent / triethyloxonium tetrafluoroborate / CH2Cl2 / Ambient temperature View Scheme

1: 93 percent / thionyl chloride, pyridine / 0.5 h / 0 °C 2: 90 percent / triethyloxonium tetrafluoroborate / CH2Cl2 / Ambient temperature View Scheme