1: 82 percent / diethyl ether / Ambient temperature 2: 56 percent / lithium di-isopropylamide, HMPA / tetrahydrofuran 3: 88 percent / KOH / methanol / 16 h / Ambient temperature 4: 20 percent / Et3N, diphenylphosphoryl azide / toluene / 7 h / Heating 5: Heating 6: 1.) O3; 2.) NaBH4 / 1.) CH2Cl2, -15 deg C, 8 min; 2.) EtOH, 0 deg C, 1.5 h View Scheme

1: 82 percent / diethyl ether / Ambient temperature 2: 56 percent / lithium di-isopropylamide, HMPA / tetrahydrofuran 3: 88 percent / KOH / methanol / 16 h / Ambient temperature 4: 20 percent / Et3N, diphenylphosphoryl azide / toluene / 7 h / Heating 5: Heating 6: 1.) O3; 2.) NaBH4 / 1.) CH2Cl2, -15 deg C, 8 min; 2.) EtOH, 0 deg C, 1.5 h View Scheme

Multi-step reaction with 4 steps 1: 91 percent / dimethylformamide / 4 h2: 68.2 g / di-isobutylaluminium hydride / hexane / 0.5 h / -60 °C3: 1.) butyl-lithium / 1.) THF, hexane, 30 min, -60 deg C; 2.) THF, RT, 1 h4: 1.) borane*THF, cyclohexane; 2.) aq. KOH, H2O2 / 1.) THF, 2 h; 2.) MeOH, RT, 1.5 h  

Multi-step reaction with 2 steps 1: 82 percent / diethyl ether / Ambient temperature2: 56 percent / lithium di-isopropylamide, HMPA / tetrahydrofuran  

Multi-step reaction with 4 steps 1: 82 percent / diethyl ether / Ambient temperature2: 56 percent / lithium di-isopropylamide, HMPA / tetrahydrofuran3: 88 percent / KOH / methanol / 16 h / Ambient temperature4: 45 percent / Et3N, diphenylphosphoryl azide / toluene / 7 h / Heating