1: 49 percent / tetraethylammonium-tetrahydridoborate / CH2Cl2 / 0.5 h 2: CH2Cl2; methanol / 15 h / Ambient temperature 3: 96 percent / Huenig base / acetonitrile / 3 h / Heating 4: 1.) sodium hydride; 2.) lithium iodide / 1.) dioxan, ethanol, 15 min; 2.) dimethylformamide, reflux, 4.5 h 5: 70 percent / borontrifluorate etherate / CHCl3 / 17 h / Ambient temperature 6: 70 percent / Raney-Ni / acetone View Scheme

Multi-step reaction with 3 steps 1: 49 percent / tetraethylammonium-tetrahydridoborate / CH2Cl2 / 0.5 h2: CH2Cl2; methanol / 15 h / Ambient temperature3: 96 percent / Huenig base / acetonitrile / 3 h / Heating  

Multi-step reaction with 4 steps 1: 49 percent / tetraethylammonium-tetrahydridoborate / CH2Cl2 / 0.5 h2: CH2Cl2; methanol / 15 h / Ambient temperature3: 96 percent / Huenig base / acetonitrile / 3 h / Heating4: 1.) sodium hydride; 2.) lithium iodide / 1.) dioxan, ethanol, 15 min; 2.) dimethylformamide, reflux, 4.5 h  

Multi-step reaction with 5 steps 1: 49 percent / tetraethylammonium-tetrahydridoborate / CH2Cl2 / 0.5 h2: CH2Cl2; methanol / 15 h / Ambient temperature3: 96 percent / Huenig base / acetonitrile / 3 h / Heating4: 1.) sodium hydride; 2.) lithium iodide / 1.) dioxan, ethanol, 15 min; 2.) dimethylformamide, reflux, 4.5 h5: 97 percent / L-selectride / CH2Cl2 / 0.25 h / -78 °C  

Multi-step reaction with 6 steps 1: 49 percent / tetraethylammonium-tetrahydridoborate / CH2Cl2 / 0.5 h2: CH2Cl2; methanol / 15 h / Ambient temperature3: 96 percent / Huenig base / acetonitrile / 3 h / Heating4: 1.) sodium hydride; 2.) lithium iodide / 1.) dioxan, ethanol, 15 min; 2.) dimethylformamide, reflux, 4.5 h5: 97 percent / L-selectride / CH2Cl2 / 0.25 h / -78 °C6: 85 percent / sodium hydride / tetrahydrofuran / 1 h / Ambient temperature  

Multi-step reaction with 5 steps 1: 49 percent / tetraethylammonium-tetrahydridoborate / CH2Cl2 / 0.5 h2: CH2Cl2; methanol / 15 h / Ambient temperature3: 96 percent / Huenig base / acetonitrile / 3 h / Heating4: 1.) sodium hydride; 2.) lithium iodide / 1.) dioxan, ethanol, 15 min; 2.) dimethylformamide, reflux, 4.5 h5: 70 percent / borontrifluorate etherate / CHCl3 / 17 h / Ambient temperature