1: 76 percent / KH / dimethylformamide 2: 72 percent / NaBH4 / methanol / 12 h 3: 1.) MsCl, Et3N, 2.) LiBr / 1.) CH2Cl2, -60 deg C, 15 min, 2.) THF, -60 to -40 deg C, 30 min 4: 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 5: 62 percent / NaBH4, CoCl2 / methanol 6: 2M NaOH / 48 h / Ambient temperature View Scheme

With  potassium hydride in  tetrahydrofuran  Ambient temperature;   

Multi-step reaction with 2 steps 1: 76 percent / KH / dimethylformamide2: 72 percent / NaBH4 / methanol / 12 h  

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 4 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 min4: 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