1: 96 percent / pyridine / 1.) 0 deg C, 30 min, 2.) RT, 20 h 2: 62 percent / pyridinium p-toluenesulfonate (PPTS) / ethanol / 4 h / 55 °C 3: 55 percent / (Et2N)(Me2N)SF2 / CCl3F / 1.) -70 deg C, 45 min, 2.) RT, 1 h 4: 83 percent / potassium carbonate / methanol / 0.17 h / Ambient temperature View Scheme

1: 96 percent / pyridine / 1.) 0 deg C, 30 min, 2.) RT, 20 h 2: 62 percent / pyridinium p-toluenesulfonate (PPTS) / ethanol / 4 h / 55 °C View Scheme

1: 96 percent / pyridine / 1.) 0 deg C, 30 min, 2.) RT, 20 h 2: 4 percent / pyridinium p-toluenesulfonate (PPTS) / ethanol / 4 h / 55 °C View Scheme

1: 96 percent / pyridine / 1.) 0 deg C, 30 min, 2.) RT, 20 h 2: 62 percent / pyridinium p-toluenesulfonate (PPTS) / ethanol / 4 h / 55 °C 3: 55 percent / (Et2N)(Me2N)SF2 / CCl3F / 1.) -70 deg C, 45 min, 2.) RT, 1 h View Scheme