1.1: 90 percent / lutidine / CH2Cl2 / 2 h / -70 - -60 °C 2.1: 93 percent / BF3*Et2O; 4 Angstroem molecular sieves / CH2Cl2 / -78 - -20 °C 3.1: NBS; H2O / CH2Cl2 / 2 h / 25 °C 3.2: 98 percent / DBU / CH2Cl2 / 12 h / 25 °C 4.1: 71 percent / TMSOTf; 4 Angstroem molecular sieves / CH2Cl2 / 5 h / -20 °C 5.1: DDQ; H2O / CH2Cl2 / 12 h / 25 °C 5.2: 81 percent / Pd(CN)2Cl2; H2O / acetone / 2 h / 25 °C View Scheme