1: 75 percent / CBr4, BaCO3, Ph3P / CH2Cl2 / 0.75 h 2: 82 percent / n-Bu3SnH, AIBN / toluene / 1 h / 65 °C 3: 98 percent / PPTs / methanol / 14 h / 22 °C 4: MnO2 / tetrahydrofuran / 5 h 5: NaCN / acetic acid / 16 h View Scheme

Multi-step reaction with 6 steps 1: Et3N, DMAP / CH2Cl2 2: NaH / tetrahydrofuran / 12 h3: O3, pyridine / CH2Cl2 5: 76 percent / PDC, 3 Angstroem molecular sieves / CH2Cl2 6: 1.) CeI3 / 1.) THF, from -100 deg C to 0 deg C, 30 min, 2.) THF  

Multi-step reaction with 7 steps 1: 1.) TsCl, DMAP, Et3N, 2.) TsOH, NaOCH3 / 1.) CH2Cl2, 22 deg C, 4 h, 2.) MeOH, 22 deg C, 16 h2: Et3N, DMAP / CH2Cl2 3: NaH / tetrahydrofuran / 12 h4: O3, pyridine / CH2Cl2 6: 76 percent / PDC, 3 Angstroem molecular sieves / CH2Cl2 7: 1.) CeI3 / 1.) THF, from -100 deg C to 0 deg C, 30 min, 2.) THF  

Multi-step reaction with 8 steps 1: 85 percent / LiAlH4 / diethyl ether / 1 h / 0 - 22 °C2: 1.) TsCl, DMAP, Et3N, 2.) TsOH, NaOCH3 / 1.) CH2Cl2, 22 deg C, 4 h, 2.) MeOH, 22 deg C, 16 h3: Et3N, DMAP / CH2Cl2 4: NaH / tetrahydrofuran / 12 h5: O3, pyridine / CH2Cl2 7: 76 percent / PDC, 3 Angstroem molecular sieves / CH2Cl2 8: 1.) CeI3 / 1.) THF, from -100 deg C to 0 deg C, 30 min, 2.) THF  

Multi-step reaction with 3 steps 2: 76 percent / PDC, 3 Angstroem molecular sieves / CH2Cl2 3: 1.) CeI3 / 1.) THF, from -100 deg C to 0 deg C, 30 min, 2.) THF  

Multi-step reaction with 4 steps 1: O3, pyridine / CH2Cl2 3: 76 percent / PDC, 3 Angstroem molecular sieves / CH2Cl2 4: 1.) CeI3 / 1.) THF, from -100 deg C to 0 deg C, 30 min, 2.) THF  

With  carbon tetrabromide; triphenylphosphine; barium carbonate in  dichloromethane 0.75 h;