1: 74 percent / aq. KOH, Bu4NHSO4 / toluene / 1.) 0 deg C, 10 min, 2.) room temp., 30 min 2: 100 percent / CF3COOH / CH2Cl2 / 2 h / Ambient temperature 3: oxalyl chloride, DMF / CH2Cl2 / 1 h / Ambient temperature 4: pyridine / CH2Cl2; tetrahydrofuran / 2 h / Ambient temperature View Scheme

1: oxalyl chloride, DMF / CH2Cl2 / 1 h / Ambient temperature 2: pyridine / CH2Cl2; tetrahydrofuran / 2 h / Ambient temperature View Scheme

1: 100 percent / CF3COOH / CH2Cl2 / 2 h / Ambient temperature 2: oxalyl chloride, DMF / CH2Cl2 / 1 h / Ambient temperature 3: pyridine / CH2Cl2; tetrahydrofuran / 2 h / Ambient temperature View Scheme

pyridine in tetrahydrofuran; dichloromethane 2 h; Ambient temperature;