1: 91 percent / pyridine / CH2Cl2 / 0.5 h 2: 91 percent / pyridine / 9 h / Ambient temperature 3: 89 percent / Li, NH3 / tetrahydrofuran / 0.5 h / -78 °C / 1.) -78 deg C, 30 min. 2.) THF, 30 min 4: 100 percent / 48percent aq. HF / acetonitrile / 1 h 5: 1.) oxalyl chloride, DMSO, 2.) Et3N / 1.) CH2Cl2, -78 deg C, 30 min., 2.) CH2Cl2, -78 deg C to room temp. 6: 51 percent / BF3 * Et2O / CH2Cl2; diethyl ether / 2 h 7: 64 percent / toluene / 10 h / Heating 8: 79 percent / 48percent aq. HF / acetonitrile / 0.25 h 9: 100 percent / NaH / CH2Cl2 / 0.5 h / Ambient temperature View Scheme

With  lithium aluminium tetrahydride in  diethyl ether 3 h;  Yield given;   

Multi-step reaction with 5 steps 1: 1.) lithium diisopropyl amide / tetrahydrofuran / -78 °C2: toluene / 10 h / Heating3: 48percent aq. HF / 1.5 h / 0 °C4: diethyl ether / 0 °C5: LiAlH4 / diethyl ether / 3 h  

Multi-step reaction with 2 steps 1: diethyl ether / 0 °C2: LiAlH4 / diethyl ether / 3 h  

Multi-step reaction with 3 steps 1: 48percent aq. HF / 1.5 h / 0 °C2: diethyl ether / 0 °C3: LiAlH4 / diethyl ether / 3 h  

Multi-step reaction with 4 steps 1: toluene / 10 h / Heating2: 48percent aq. HF / 1.5 h / 0 °C3: diethyl ether / 0 °C4: LiAlH4 / diethyl ether / 3 h  

Multi-step reaction with 2 steps 1: 91 percent / pyridine / CH2Cl2 / 0.5 h2: 91 percent / pyridine / 9 h / Ambient temperature  

Multi-step reaction with 3 steps 1: 91 percent / pyridine / CH2Cl2 / 0.5 h2: 91 percent / pyridine / 9 h / Ambient temperature3: 89 percent / Li, NH3 / tetrahydrofuran / 0.5 h / -78 °C / 1.) -78 deg C, 30 min. 2.) THF, 30 min  

Multi-step reaction with 4 steps 1: 91 percent / pyridine / CH2Cl2 / 0.5 h2: 91 percent / pyridine / 9 h / Ambient temperature3: 89 percent / Li, NH3 / tetrahydrofuran / 0.5 h / -78 °C / 1.) -78 deg C, 30 min. 2.) THF, 30 min4: 100 percent / 48percent aq. HF / acetonitrile / 1 h  

Multi-step reaction with 8 steps 1: 91 percent / pyridine / CH2Cl2 / 0.5 h2: 91 percent / pyridine / 9 h / Ambient temperature3: 89 percent / Li, NH3 / tetrahydrofuran / 0.5 h / -78 °C / 1.) -78 deg C, 30 min. 2.) THF, 30 min4: 100 percent / 48percent aq. HF / acetonitrile / 1 h5: 1.) oxalyl chloride, DMSO, 2.) Et3N / 1.) CH2Cl2, -78 deg C, 30 min., 2.) CH2Cl2, -78 deg C to room temp.6: 51 percent / BF3 * Et2O / CH2Cl2; diethyl ether / 2 h7: 64 percent / toluene / 10 h / Heating8: 79 percent / 48percent aq. HF / acetonitrile / 0.25 h