1: 1,4-diazabicyclo<2.2.2>octane 2: 95 percent / p-toluenesulfonic acid / benzene / Heating 3: 98 percent / lithium diisopropylamide / tetrahydrofuran / 2 h / -78 °C View Scheme

1: 1,4-diazabicyclo<2.2.2>octane 2: 95 percent / p-toluenesulfonic acid / benzene / Heating 3: 98 percent / lithium diisopropylamide / tetrahydrofuran / 2 h / -78 °C 4: 37 percent / titanium tetrachloride / CH2Cl2 / 6 h / -78 °C View Scheme

iodine in tetrahydrofuran -78°C; chromy. (n-hexane/CHCl3, silica gel);

1: 1,4-diazabicyclo<2.2.2>octane 2: 95 percent / p-toluenesulfonic acid / benzene / Heating 3: 98 percent / lithium diisopropylamide / tetrahydrofuran / 2 h / -78 °C 4: aluminum chloride / CH2Cl2 / 6 h / -78 °C View Scheme

1: 1,4-diazabicyclo<2.2.2>octane 2: 95 percent / p-toluenesulfonic acid / benzene / Heating View Scheme

1: 1,4-diazabicyclo<2.2.2>octane 2: 95 percent / p-toluenesulfonic acid / benzene / Heating 3: 98 percent / lithium diisopropylamide / tetrahydrofuran / 2 h / -78 °C 4: aluminum chloride / CH2Cl2 / 6 h / -78 °C View Scheme