1: 1.) lithium diisopropyl amide / tetrahydrofuran / -78 °C 2: toluene / 10 h / Heating 3: 48percent aq. HF / 1.5 h / 0 °C 4: diethyl ether / 0 °C 5: LiAlH4 / diethyl ether / 3 h 6: 91 percent / pyridine / CH2Cl2 / 0.5 h 7: 91 percent / pyridine / 9 h / Ambient temperature 8: 89 percent / Li, NH3 / tetrahydrofuran / 0.5 h / -78 °C / 1.) -78 deg C, 30 min. 2.) THF, 30 min 9: 100 percent / 48percent aq. HF / acetonitrile / 1 h 10: 1.) oxalyl chloride, DMSO, 2.) Et3N / 1.) CH2Cl2, -78 deg C, 30 min., 2.) CH2Cl2, -78 deg C to room temp. 11: 51 percent / BF3 * Et2O / CH2Cl2; diethyl ether / 2 h 12: 64 percent / toluene / 10 h / Heating 13: 79 percent / 48percent aq. HF / acetonitrile / 0.25 h 14: 100 percent / NaH / CH2Cl2 / 0.5 h / Ambient temperature View Scheme

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 4 steps 1: 1.) lithium diisopropyl amide / tetrahydrofuran / -78 °C2: toluene / 10 h / Heating3: 48percent aq. HF / 1.5 h / 0 °C4: diethyl ether / 0 °C  

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 6 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 h6: 91 percent / pyridine / CH2Cl2 / 0.5 h  

Multi-step reaction with 7 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 h6: 91 percent / pyridine / CH2Cl2 / 0.5 h7: 91 percent / pyridine / 9 h / Ambient temperature  

Multi-step reaction with 8 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 h6: 91 percent / pyridine / CH2Cl2 / 0.5 h7: 91 percent / pyridine / 9 h / Ambient temperature8: 89 percent / Li, NH3 / tetrahydrofuran / 0.5 h / -78 °C / 1.) -78 deg C, 30 min. 2.) THF, 30 min  

Multi-step reaction with 9 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 h6: 91 percent / pyridine / CH2Cl2 / 0.5 h7: 91 percent / pyridine / 9 h / Ambient temperature8: 89 percent / Li, NH3 / tetrahydrofuran / 0.5 h / -78 °C / 1.) -78 deg C, 30 min. 2.) THF, 30 min9: 100 percent / 48percent aq. HF / acetonitrile / 1 h  

Multi-step reaction with 13 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 h6: 91 percent / pyridine / CH2Cl2 / 0.5 h7: 91 percent / pyridine / 9 h / Ambient temperature8: 89 percent / Li, NH3 / tetrahydrofuran / 0.5 h / -78 °C / 1.) -78 deg C, 30 min. 2.) THF, 30 min9: 100 percent / 48percent aq. HF / acetonitrile / 1 h10: 1.) oxalyl chloride, DMSO, 2.) Et3N / 1.) CH2Cl2, -78 deg C, 30 min., 2.) CH2Cl2, -78 deg C to room temp.11: 51 percent / BF3 * Et2O / CH2Cl2; diethyl ether / 2 h12: 64 percent / toluene / 10 h / Heating13: 79 percent / 48percent aq. HF / acetonitrile / 0.25 h  

Multi-step reaction with 2 steps 1: 1.) lithium diisopropyl amide / tetrahydrofuran / -78 °C2: toluene / 10 h / Heating