lithium diisopropyl amide in tetrahydrofuran T=-78°C; 4 h;

1: 95 percent / p-toluenesulfonic acid / benzene / Heating 2: 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 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 View Scheme

1: 91 percent / 1,4-diazabicyclo<2.2.2>octane, n-butyllithium / tetrahydrofuran; hexane / 0 degC for 15 min and room t. for 1.5 h, then 0 degC, 1 h, room t., 1 h 2: 95 percent / p-toluenesulfonic acid / benzene / 7 h / Heating 3: 98 percent / lithium diisopropylamide / tetrahydrofuran / 4 h / -78 °C View Scheme

titanium tetrachloride in dichloromethane T=-78°C; 6 h;

aluminium trichloride in dichloromethane T=-78°C; 6 h;

aluminium trichloride in dichloromethane T=-78°C; 6 h;