1: 72 percent / ceric ammonium nitrate (CAN) / acetonitrile; H2O / 0.5 h / Ambient temperature 2: 1.) boron trifluoride etherate, NaBH4, 1,5-cyclooctadiene, 2.) 35percent aq. H2O2, aq. NaOH / 1.) THF, 3 h, 2.) THF, 40-45 deg C 3: 84 percent / CrO3, aq. H2SO4 / acetone / 10 - 20 °C 4: H2 / 10percent Pd/C / ethanol / 4 h / Ambient temperature 5: imidazole / dimethylformamide / 15 h / Ambient temperature 6: aq. K2CO3 / methanol; tetrahydrofuran / 0.5 h / Ambient temperature View Scheme

With  pyridine; thionyl chloride in  toluene T=20 - 30°C; 5 h;   

Multi-step reaction with 2 steps 1: 72 percent / ceric ammonium nitrate (CAN) / acetonitrile; H2O / 0.5 h / Ambient temperature2: 1.) boron trifluoride etherate, NaBH4, 1,5-cyclooctadiene, 2.) 35percent aq. H2O2, aq. NaOH / 1.) THF, 3 h, 2.) THF, 40-45 deg C  

Multi-step reaction with 5 steps 1: 72 percent / ceric ammonium nitrate (CAN) / acetonitrile; H2O / 0.5 h / Ambient temperature2: 1.) boron trifluoride etherate, NaBH4, 1,5-cyclooctadiene, 2.) 35percent aq. H2O2, aq. NaOH / 1.) THF, 3 h, 2.) THF, 40-45 deg C3: 84 percent / CrO3, aq. H2SO4 / acetone / 10 - 20 °C4: H2 / 10percent Pd/C / ethanol / 4 h / Ambient temperature5: imidazole / dimethylformamide / 15 h / Ambient temperature