1: lithium / liquid ammonia; tetrahydrofuran / 1.5 h / -78 °C 2: N,N-diethylcyclohexylamine / dioxane / 1.) 50 deg C, 6 h; 2.) 80 deg C, 2 h 3: aq. HCl; tetrahydrofuran; methanol / Ambient temperature 4: 73 percent / pyridine / 0.5 h / 0 °C 5: 85 percent / dimethylsulfoxide / 4 h / 90 - 100 °C 6: potassium hydroxide / H2O; ethanol / 2 h / Heating 7: methanol; diethyl ether / 1 h / Ambient temperature 8: 81 percent / tetrahydrofuran / 1.) 0 deg C, 30 min; 2.) rt, 4.5 h 9: 82 percent / aq. HCl; tetrahydrofuran / 72 h / Ambient temperature 10: 74 percent / pyridine 11: N-bromosuccinimide / CCl4 / 0.33 h / Heating 12: tetra-n-butylammonium fluoride / tetra-n-butylammonium bromide / tetrahydrofuran 13: potassium hydroxide / tetrahydrofuran; methanol View Scheme

Multi-step reaction with 3 steps 1: lithium / liquid ammonia; tetrahydrofuran / 1.5 h / -78 °C2: N,N-diethylcyclohexylamine / dioxane / 1.) 50 deg C, 6 h; 2.) 80 deg C, 2 h3: aq. HCl; tetrahydrofuran; methanol / Ambient temperature  

Multi-step reaction with 9 steps 1: lithium / liquid ammonia; tetrahydrofuran / 1.5 h / -78 °C2: N,N-diethylcyclohexylamine / dioxane / 1.) 50 deg C, 6 h; 2.) 80 deg C, 2 h3: aq. HCl; tetrahydrofuran; methanol / Ambient temperature4: 73 percent / pyridine / 0.5 h / 0 °C5: 85 percent / dimethylsulfoxide / 4 h / 90 - 100 °C6: potassium hydroxide / H2O; ethanol / 2 h / Heating7: methanol; diethyl ether / 1 h / Ambient temperature8: 81 percent / tetrahydrofuran / 1.) 0 deg C, 30 min; 2.) rt, 4.5 h9: 82 percent / aq. HCl; tetrahydrofuran / 72 h / Ambient temperature  

Multi-step reaction with 7 steps 1: lithium / liquid ammonia; tetrahydrofuran / 1.5 h / -78 °C2: N,N-diethylcyclohexylamine / dioxane / 1.) 50 deg C, 6 h; 2.) 80 deg C, 2 h3: aq. HCl; tetrahydrofuran; methanol / Ambient temperature4: 73 percent / pyridine / 0.5 h / 0 °C5: 85 percent / dimethylsulfoxide / 4 h / 90 - 100 °C6: potassium hydroxide / H2O; ethanol / 2 h / Heating7: methanol; diethyl ether / 1 h / Ambient temperature  

Multi-step reaction with 8 steps 1: lithium / liquid ammonia; tetrahydrofuran / 1.5 h / -78 °C2: N,N-diethylcyclohexylamine / dioxane / 1.) 50 deg C, 6 h; 2.) 80 deg C, 2 h3: aq. HCl; tetrahydrofuran; methanol / Ambient temperature4: 73 percent / pyridine / 0.5 h / 0 °C5: 85 percent / dimethylsulfoxide / 4 h / 90 - 100 °C6: potassium hydroxide / H2O; ethanol / 2 h / Heating7: methanol; diethyl ether / 1 h / Ambient temperature8: 81 percent / tetrahydrofuran / 1.) 0 deg C, 30 min; 2.) rt, 4.5 h  

Multi-step reaction with 2 steps 1: lithium / liquid ammonia; tetrahydrofuran / 1.5 h / -78 °C2: N,N-diethylcyclohexylamine / dioxane / 1.) 50 deg C, 6 h; 2.) 80 deg C, 2 h  

Multi-step reaction with 6 steps 1: lithium / liquid ammonia; tetrahydrofuran / 1.5 h / -78 °C2: N,N-diethylcyclohexylamine / dioxane / 1.) 50 deg C, 6 h; 2.) 80 deg C, 2 h3: aq. HCl; tetrahydrofuran; methanol / Ambient temperature4: 73 percent / pyridine / 0.5 h / 0 °C5: 85 percent / dimethylsulfoxide / 4 h / 90 - 100 °C6: potassium hydroxide / H2O; ethanol / 2 h / Heating