1: 97 percent / sodium iodide; trimethylsilyl chloride / acetonitrile / 24 h / 20 °C 2: 85 percent / cesium carbonate / dimethylsulfoxide / 3 h / 65 °C 3: 73 percent / trifluoroacetic acid / toluene / 24 h / 75 °C 4: 80 percent / acetic acid / 4 h / 100 °C 5: 88 percent / tetra-n-butylammonium iodide; boron tribromide / CH2Cl2 / 0.5 h / -40 °C 6: 62 percent / pyridinium chlorochromate; celite; isopropyl alcohol / CH2Cl2 / 1 h / 20 °C View Scheme