1: 94 percent / pyridine, dimethylaminopyridine / 0 degC then 1 h, room temperature 2: 78 percent / NaI, Na2S2O3 / acetone / Ambient temperature 3: acetonitrile / 11 h, room temperature then 36 h, 40 degC 4: 1.) n-BuLi / 1.) THF/HMPA/hexane, -78 degC, 20 min; 2.) THF/HMPA/hexane/Et2O, -78 degC, 1.5 h then room temperature, 2 h 5: H2 / PtO2 / ethanol / 1.75 h / Ambient temperature View Scheme

1: 94 percent / CBr4, Ph3P / CH2Cl2 / 1.) 0 deg C, 15 min, 2.) room temperature, 1 h 2: 95 percent / acetonitrile / Heating 3: 76 percent / NaN(SiMe3)2 / tetrahydrofuran / -80 °C 4: 92 percent / LiOH / tetrahydrofuran; H2O View Scheme

1: 94 percent / CBr4, Ph3P / CH2Cl2 / 1.) 0 deg C, 15 min, 2.) room temperature, 1 h 2: 95 percent / acetonitrile / Heating 3: 76 percent / NaN(SiMe3)2 / tetrahydrofuran / -80 °C View Scheme