1: 9.5 kg / NaBH4; aq. NaOH / ethyl acetate / 3 h / 20 - 25 °C 2: 94.8 percent / PBr3 / CH2Cl2 / 2 h / 20 °C 3: 88 percent / CH2Cl2; dimethylsulfoxide / 25 h / 30 °C 4: LiBH4; TFA / ethyl acetate; tetrahydrofuran / 3.5 h / 10 - 25 °C View Scheme

1: triethylene glycol dimethyl ether / 180 °C 2: 9.5 kg / NaBH4; aq. NaOH / ethyl acetate / 3 h / 20 - 25 °C 3: 94.8 percent / PBr3 / CH2Cl2 / 2 h / 20 °C 4: 88 percent / CH2Cl2; dimethylsulfoxide / 25 h / 30 °C 5: LiBH4; TFA / ethyl acetate; tetrahydrofuran / 3.5 h / 10 - 25 °C View Scheme

in acetonitrile T=50°C; 18 h; Product distribution; Further Variations:Solvents;