pyridine; bromine; triphenylphosphine in dichloromethane T=20°C; 18 h;

1.1: 86 percent / Bu3SnOMe / 50 °C / 75.01 Torr 2.1: lithium 2,2,6,6-tetramethylpiperidine / tetrahydrofuran; hexane / 0.67 h / -70 - -60 °C 2.2: 74 percent / BF3*OEt2 / tetrahydrofuran; hexane / 10 h / 20 °C View Scheme