1: With triphenylphosphine in tetrahydrofuran 2 h; 2: With water in tetrahydrofuran

1.1: 85 percent / NaN3; 18-crown-6 / acetonitrile 2.1: triphenylphosphine / tetrahydrofuran / 2 h 2.2: 95 percent / H2O / tetrahydrofuran View Scheme

1.1: 88 percent / POBr3 / 60 - 120 °C 2.1: n-BuLi / tetrahydrofuran; hexane / -78 °C 2.2: tetrahydrofuran; hexane / 0.5 h / -78 °C 3.1: 85 percent / NaBH4; acetic acid / tetrahydrofuran; hexane; methanol / -78 - 20 °C 4.1: triethylamine / CH2Cl2 / 3 h / -30 °C 5.1: 85 percent / NaN3; 18-crown-6 / acetonitrile 6.1: triphenylphosphine / tetrahydrofuran / 2 h 6.2: 95 percent / H2O / tetrahydrofuran View Scheme

1.1: n-BuLi / tetrahydrofuran; hexane / -78 °C 1.2: tetrahydrofuran; hexane / 0.5 h / -78 °C 2.1: 85 percent / NaBH4; acetic acid / tetrahydrofuran; hexane; methanol / -78 - 20 °C 3.1: triethylamine / CH2Cl2 / 3 h / -30 °C 4.1: 85 percent / NaN3; 18-crown-6 / acetonitrile 5.1: triphenylphosphine / tetrahydrofuran / 2 h 5.2: 95 percent / H2O / tetrahydrofuran View Scheme

1.1: 85 percent / NaBH4; acetic acid / tetrahydrofuran; hexane; methanol / -78 - 20 °C 2.1: triethylamine / CH2Cl2 / 3 h / -30 °C 3.1: 85 percent / NaN3; 18-crown-6 / acetonitrile 4.1: triphenylphosphine / tetrahydrofuran / 2 h 4.2: 95 percent / H2O / tetrahydrofuran View Scheme

1.1: triethylamine / CH2Cl2 / 3 h / -30 °C 2.1: 85 percent / NaN3; 18-crown-6 / acetonitrile 3.1: triphenylphosphine / tetrahydrofuran / 2 h 3.2: 95 percent / H2O / tetrahydrofuran View Scheme