1: diethyl ether / 0 °C 2: LiAlH4 / diethyl ether / 3 h 3: 91 percent / pyridine / CH2Cl2 / 0.5 h 4: 91 percent / pyridine / 9 h / Ambient temperature 5: 89 percent / Li, NH3 / tetrahydrofuran / 0.5 h / -78 °C / 1.) -78 deg C, 30 min. 2.) THF, 30 min 6: 100 percent / 48percent aq. HF / acetonitrile / 1 h 7: 1.) oxalyl chloride, DMSO, 2.) Et3N / 1.) CH2Cl2, -78 deg C, 30 min., 2.) CH2Cl2, -78 deg C to room temp. 8: 51 percent / BF3 * Et2O / CH2Cl2; diethyl ether / 2 h 9: 64 percent / toluene / 10 h / Heating 10: 79 percent / 48percent aq. HF / acetonitrile / 0.25 h 11: 100 percent / NaH / CH2Cl2 / 0.5 h / Ambient temperature View Scheme

With  hydrogen fluoride T=0°C; 1.5 h;   

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

Multi-step reaction with 2 steps 1: toluene / 10 h / Heating2: 48percent aq. HF / 1.5 h / 0 °C  

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

Multi-step reaction with 3 steps 1: diethyl ether / 0 °C2: LiAlH4 / diethyl ether / 3 h3: 91 percent / pyridine / CH2Cl2 / 0.5 h  

Multi-step reaction with 4 steps 1: diethyl ether / 0 °C2: LiAlH4 / diethyl ether / 3 h3: 91 percent / pyridine / CH2Cl2 / 0.5 h4: 91 percent / pyridine / 9 h / Ambient temperature  

Multi-step reaction with 5 steps 1: diethyl ether / 0 °C2: LiAlH4 / diethyl ether / 3 h3: 91 percent / pyridine / CH2Cl2 / 0.5 h4: 91 percent / pyridine / 9 h / Ambient temperature5: 89 percent / Li, NH3 / tetrahydrofuran / 0.5 h / -78 °C / 1.) -78 deg C, 30 min. 2.) THF, 30 min  

Multi-step reaction with 6 steps 1: diethyl ether / 0 °C2: LiAlH4 / diethyl ether / 3 h3: 91 percent / pyridine / CH2Cl2 / 0.5 h4: 91 percent / pyridine / 9 h / Ambient temperature5: 89 percent / Li, NH3 / tetrahydrofuran / 0.5 h / -78 °C / 1.) -78 deg C, 30 min. 2.) THF, 30 min6: 100 percent / 48percent aq. HF / acetonitrile / 1 h  

Multi-step reaction with 10 steps 1: diethyl ether / 0 °C2: LiAlH4 / diethyl ether / 3 h3: 91 percent / pyridine / CH2Cl2 / 0.5 h4: 91 percent / pyridine / 9 h / Ambient temperature5: 89 percent / Li, NH3 / tetrahydrofuran / 0.5 h / -78 °C / 1.) -78 deg C, 30 min. 2.) THF, 30 min6: 100 percent / 48percent aq. HF / acetonitrile / 1 h7: 1.) oxalyl chloride, DMSO, 2.) Et3N / 1.) CH2Cl2, -78 deg C, 30 min., 2.) CH2Cl2, -78 deg C to room temp.8: 51 percent / BF3 * Et2O / CH2Cl2; diethyl ether / 2 h9: 64 percent / toluene / 10 h / Heating10: 79 percent / 48percent aq. HF / acetonitrile / 0.25 h