1: pyridine / 0 degC, 6 h then 30 min, room temperature 2: 79 percent / NaI, Na2S2O3 / acetone / Ambient temperature 3: 91 percent / acetonitrile / 14 h, room temperature then 24 h, 50 degC 4: 1.) n-BuLi / 1.) THF/HMPA/hexane, -78 degC, 20 min; 2.) THF/HMPA/hexane/Et2O, -78 degC, 1 h then room temperature, 1 h 5: H2 / PtO2 / ethanol / 1.75 h / Ambient temperature View Scheme

1: 92 percent / CBr4; DIPHOS 2: 96 percent / acetonitrile 3: 70 percent / LiHDMS / tetrahydrofuran / -78 - 20 °C View Scheme

1: N(C2H5)3 2: NaI / acetone 3: toluene / anion exchange by AG 1-X8 resin 4: 46 percent / nBuLi / tetrahydrofuran; hexamethylphosphoric acid triamide / -78 °C 5: K2CO3 / H2O; methanol View Scheme

p-toluenesulfonyl chloride; sodium iodide 1.)pyridine, 2.)acetone; Multistep reaction;