1: 82 percent / triphenylphosphine; Br2; 2,6-lutidine / CH2Cl2 / 2 h / 0 - 10 °C 2: 94 percent / LiHMDS; hexamethylphosphoramide / tetrahydrofuran / 2.25 h / -78 °C 3: 85 percent / tetrabutylammonium fluoride / tetrahydrofuran / 20 h / 0 °C View Scheme