1: 1.) n-BuLi, 2.) CuBr*Me2S / 1.) -78 deg C, 30 min, 2.) -78 to -40 deg C, 30 min, 3.) -40 to -20 deg C, 1 h 2: 62 percent / NaBH4, CoCl2 / methanol 3: 2M NaOH / 48 h / Ambient temperature View Scheme

Multi-step reaction with 3 steps 1: 76 percent / KH / dimethylformamide2: 72 percent / NaBH4 / methanol / 12 h3: 1.) MsCl, Et3N, 2.) LiBr / 1.) CH2Cl2, -60 deg C, 15 min, 2.) THF, -60 to -40 deg C, 30 min  

Multi-step reaction with 2 steps 1: 72 percent / NaBH4 / methanol / 12 h2: 1.) MsCl, Et3N, 2.) LiBr / 1.) CH2Cl2, -60 deg C, 15 min, 2.) THF, -60 to -40 deg C, 30 min  

Multi-step reaction with 4 steps 1: 80 percent / KH / tetrahydrofuran / Ambient temperature2: 76 percent / KH / dimethylformamide3: 72 percent / NaBH4 / methanol / 12 h4: 1.) MsCl, Et3N, 2.) LiBr / 1.) CH2Cl2, -60 deg C, 15 min, 2.) THF, -60 to -40 deg C, 30 min  

With  methanesulfonyl chloride; triethylamine; lithium bromide  1.) CH2Cl2, -60 deg C, 15 min, 2.) THF, -60 to -40 deg C, 30 min;  Yield given. Multistep reaction;   

With  triethylamine; lithium bromide  1) dichloromethane, -60 deg C, 0.25h, 2) tetrahydrofuran, -60 to -40 deg C, 0.5h;  Yield given. Multistep reaction;