1: 98 percent / d-camphorsulfonic acid, Et3N / methanol / Ambient temperature 2: 94 percent / pyridine, dimethylaminopyridine / 0 degC then 1 h, room temperature 3: 78 percent / NaI, Na2S2O3 / acetone / Ambient temperature 4: acetonitrile / 11 h, room temperature then 36 h, 40 degC 5: 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 6: H2 / PtO2 / ethanol / 1.75 h / Ambient temperature View Scheme