lithium aluminium tetrahydride in diethyl ether T=0 - 20°C; 2 h;

diisobutylaluminium hydride in diethyl ether T=-78°C; 1 h;

1: 98 percent / DIBAH / diethyl ether / 1 h / -78 °C 2: 86 percent / Et3N, LiBr / acetonitrile / 12 h / 0 - 20 °C View Scheme

Multi-step reaction with 7 steps 1: 82 percent / 1.) diisobutylaluminium hydride / 1.) hexane, ether, -78 deg C, 10 min; 2.) MeOH, H2O, r.t., 1 h2: MgSO4 / toluene / 1 h / 0 °C3: imidazole / CH2Cl2 / 69 h / -35 °C4: 1M potassium triethylborohydride / tetrahydrofuran / 1 h / -78 °C5: 91 percent / diethyl azodicarboxylate; triphenylphosphine / tetrahydrofuran / 2 h / Ambient temperature6: 5.1 mg / K2CO3 / methanol / 0.17 h / Ambient temperature7: 95 percent / 4-(dimethylamino)pyridine / CH2Cl2 / 24 h / Ambient temperature  

Multi-step reaction with 8 steps 1: 82 percent / 1.) diisobutylaluminium hydride / 1.) hexane, ether, -78 deg C, 10 min; 2.) MeOH, H2O, r.t., 1 h2: MgSO4 / toluene / 1 h / 0 °C3: imidazole / CH2Cl2 / 69 h / -35 °C4: 1M potassium triethylborohydride / tetrahydrofuran / 1 h / -78 °C5: 91 percent / diethyl azodicarboxylate; triphenylphosphine / tetrahydrofuran / 2 h / Ambient temperature6: 5.1 mg / K2CO3 / methanol / 0.17 h / Ambient temperature7: 93 percent / CAN / acetonitrile; H2O / 3 h / -10 °C8: 97 percent / imidazole / dimethylformamide / 12 h / Ambient temperature