1: 98 percent / PPTs / methanol / 14 h / 22 °C 2: MnO2 / tetrahydrofuran / 5 h 3: NaCN / acetic acid / 16 h View Scheme

With  pyridinium p-toluenesulfonate in  methanol T=22°C; 14 h;   

With  2,2'-azo-bisisobutyronitrile; tri-n-butyl-tin hydride in  toluene T=65°C; 1 h;   

Multi-step reaction with 8 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.) THF7: 75 percent / CBr4, BaCO3, Ph3P / CH2Cl2 / 0.75 h8: 82 percent / n-Bu3SnH, AIBN / toluene / 1 h / 65 °C  

Multi-step reaction with 9 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.) THF8: 75 percent / CBr4, BaCO3, Ph3P / CH2Cl2 / 0.75 h9: 82 percent / n-Bu3SnH, AIBN / toluene / 1 h / 65 °C  

Multi-step reaction with 10 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.) THF9: 75 percent / CBr4, BaCO3, Ph3P / CH2Cl2 / 0.75 h10: 82 percent / n-Bu3SnH, AIBN / toluene / 1 h / 65 °C