Multi-step reaction with 6 steps 1: 8 percent / trimethylsilyl triflate / 1,2-dichloro-ethane / 0.5 h / 0 °C2: 88 percent / diethylaminosulfur trifluoride / toluene; 1,2-dichloro-ethane / 40 °C3: 42 percent / n-Bu3SnOTf, molecular sieves 4 A / CCl4 / 16 h / Ambient temperature4: 82 percent / n-Bu3SuH, AIBN / toluene5: H2 / Pd/C / methanol6: DMAP, pyridine