1: cesium acetate / dimethylformamide 2: NBS*H2O 3: 65 percent / DIBAL-H / benzene; toluene 4: 87 percent / LiN(TMS)2 / tetrahydrofuran / -78 °C 5: 93 percent / BF3*OEt2 / dimethylsulfoxide 6: 71 percent / CH3SO3H / dimethylsulfoxide / 1.5 h / 20 °C 7: 54 percent / DCC; DMAP / tetrahydrofuran 8: 73 percent / TFA; water View Scheme