1.1: sodium hydride / tetrahydrofuran / 1 h / 0 °C / |Inert atmosphere 2.1: triethylamine / dichloromethane / 0.75 h / 0 °C 3.1: sodium azide / ethanol; water / 8 h / |Reflux 4.1: triphenylphosphine / tetrahydrofuran / 4 h / 20 °C 4.2: Staudinger Azide Reduction / 24 h / 20 °C View Scheme

1.1: sodium hydride / tetrahydrofuran / 1 h / 0 °C / |Inert atmosphere 2.1: triethylamine / dichloromethane / 0.75 h / 0 °C 3.1: sodium azide / ethanol; water / 8 h / |Reflux 4.1: triphenylphosphine / tetrahydrofuran / 4 h / 20 °C 4.2: Staudinger Azide Reduction / 24 h / 20 °C 5.1: phosphoric acid / ethanol / 0 - 50 °C View Scheme

1: sodium hydride / tetrahydrofuran / 1 h / 0 °C / |Inert atmosphere 2: triethylamine / dichloromethane / 0.75 h / 0 °C 3: sodium azide / ethanol; water / 8 h / |Reflux View Scheme