pyridinium p-toluenesulfonate in benzene Ambient temperature;

1: DMAP, Et3N 2: Dibal-H / CH2Cl2; diethyl ether 3: 74 percent / pyridine 4: 91 percent / 1.5 h / 190 °C / 0.5 Torr / Heating 5: 1.) t-BuLi, 2.) BF3*OEt2 / 1.) THF, pentane, -78 deg C, 1 h, 2.) THF, pentane, ether, -78 deg C, 30 min, then -10 deg C, 30 min 6: 35 percent / pyridinium p-toluenesulfonate / benzene / Ambient temperature View Scheme

1: DMAP, Et3N 2: Dibal-H / CH2Cl2; diethyl ether 3: 74 percent / pyridine 4: 91 percent / 1.5 h / 190 °C / 0.5 Torr / Heating 5: 1.) t-BuLi, 2.) BF3*OEt2 / 1.) THF, pentane, -78 deg C, 1 h, 2.) THF, pentane, ether, -78 deg C, 30 min, then -10 deg C, 30 min 6: 35 percent / pyridinium p-toluenesulfonate / benzene / Ambient temperature View Scheme

1: Dibal-H / CH2Cl2; diethyl ether 2: 74 percent / pyridine 3: 91 percent / 1.5 h / 190 °C / 0.5 Torr / Heating 4: 1.) t-BuLi, 2.) BF3*OEt2 / 1.) THF, pentane, -78 deg C, 1 h, 2.) THF, pentane, ether, -78 deg C, 30 min, then -10 deg C, 30 min 5: 35 percent / pyridinium p-toluenesulfonate / benzene / Ambient temperature View Scheme

1: 74 percent / pyridine 2: 91 percent / 1.5 h / 190 °C / 0.5 Torr / Heating 3: 1.) t-BuLi, 2.) BF3*OEt2 / 1.) THF, pentane, -78 deg C, 1 h, 2.) THF, pentane, ether, -78 deg C, 30 min, then -10 deg C, 30 min 4: 35 percent / pyridinium p-toluenesulfonate / benzene / Ambient temperature View Scheme