in hexane; diethylene glycol dimethyl ether; acetone

1: With di-isopropyl azodicarboxylate; triphenylphosphine in tetrahydrofuran T=-30 - 60°C; Mitsunobu reaction; 5 h; 2: With sodium hydroxide in tetrahydrofuran T=65°C; 7 h;

in triglyme (triethylene glycol dimethyl ether) T=180°C;

in triglyme (triethylene glycol dimethyl ether) T=180°C;

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