1.1: diisopropylamine; butyllithium / hexane; tetrahydrofuran / 2 h / -75 °C 1.2: 89 percent / hexane; tetrahydrofuran 2.1: 96 percent / bromine / CCl4 / 12 h / Heating 3.1: diisopropylamine / hexane; tetrahydrofuran / 2 h / -75 °C 3.2: butyllithium / tetrahydrofuran; diethyl ether; hexane / 0.25 h / -100 °C 3.3: 49 percent / butyllithium / hexane; diethyl ether / 0.25 h / -100 °C 4.1: butyllithium / hexane; tetrahydrofuran / 0.25 h / -75 °C 4.2: hexane; tetrahydrofuran View Scheme

1.1: diisopropylamine; butyllithium / hexane; tetrahydrofuran / 2 h / -75 °C 1.2: 89 percent / hexane; tetrahydrofuran 2.1: 96 percent / bromine / CCl4 / 12 h / Heating 3.1: diisopropylamine / hexane; tetrahydrofuran / 2 h / -75 °C 3.2: butyllithium / tetrahydrofuran; diethyl ether; hexane / 0.25 h / -100 °C 3.3: 49 percent / butyllithium / hexane; diethyl ether / 0.25 h / -100 °C View Scheme

1.1: diisopropylamine; butyllithium / hexane; tetrahydrofuran / 2 h / -75 °C 1.2: 89 percent / hexane; tetrahydrofuran 2.1: 96 percent / bromine / CCl4 / 12 h / Heating 3.1: diisopropylamine / hexane; tetrahydrofuran / 2 h / -75 °C 3.2: butyllithium / tetrahydrofuran; diethyl ether; hexane / 0.25 h / -100 °C View Scheme