1: 92 percent / sec-butyllithium; bromine / cyclohexane; tetrahydrofuran / 0.75 h 2: 82 percent / diisopropylamine; butyllithium / hexane; tetrahydrofuran / -75 °C 3: diisopropylamine; butyllithium / hexane; tetrahydrofuran / 2 h / -75 °C 4: 59 percent / butyllithium / diethyl ether; hexane / 0.25 h / -100 °C 5: 93 percent / butyllithium / hexane; diethyl ether / 0.25 h / -75 °C View Scheme

1: 92 percent / sec-butyllithium; bromine / cyclohexane; tetrahydrofuran / 0.75 h 2: 70 percent / diisopropylamine; butyllithium / hexane; tetrahydrofuran / 2 h / -75 °C View Scheme

1: 92 percent / sec-butyllithium; bromine / cyclohexane; tetrahydrofuran / 0.75 h 2: 82 percent / diisopropylamine; butyllithium / hexane; tetrahydrofuran / -75 °C 3: butyllithium / hexane; diethyl ether / 0.25 h / -100 °C View Scheme

1: 92 percent / sec-butyllithium; bromine / cyclohexane; tetrahydrofuran / 0.75 h 2: 86 percent / diisopropylamine; butyllithium; iodine / tetrahydrofuran; hexane / 2 h / -75 °C View Scheme

1: 92 percent / sec-butyllithium; bromine / cyclohexane; tetrahydrofuran / 0.75 h 2: 86 percent / diisopropylamine; butyllithium; iodine / tetrahydrofuran; hexane / 2 h / -75 °C 3: diisopropylamine; BuLi / hexane; tetrahydrofuran / 2 h / -75 °C View Scheme

1: 92 percent / sec-butyllithium; bromine / cyclohexane; tetrahydrofuran / 0.75 h 2: 86 percent / diisopropylamine; butyllithium; iodine / tetrahydrofuran; hexane / 2 h / -75 °C 3: diisopropylamine; BuLi / hexane; tetrahydrofuran / 2 h / -75 °C 4: 91 percent / butyllithium / diethyl ether; hexane / 0.25 h / -100 °C View Scheme