1: With n-butyllithium; diisopropylamine in tetrahydrofuran; hexane T=-75°C; 2 h; 2: With iodine in tetrahydrofuran; hexane

1.1: sec-butyllithium / tetrahydrofuran; hexane / 2 h / -75 °C 1.2: 92 percent / bromine / tetrahydrofuran; hexane 2.1: 89 percent / 2,2,6,6-tetramethylpiperidine; butyllithium / tetrahydrofuran; hexane / 6 h / -75 °C 3.1: diisopropylamine; butyllithium / tetrahydrofuran; hexane / 2 h / -75 °C 3.2: 80 percent / iodine / tetrahydrofuran; hexane View Scheme

1.1: 89 percent / 2,2,6,6-tetramethylpiperidine; butyllithium / tetrahydrofuran; hexane / 6 h / -75 °C 2.1: diisopropylamine; butyllithium / tetrahydrofuran; hexane / 2 h / -75 °C 2.2: 80 percent / iodine / tetrahydrofuran; hexane View Scheme