1.1: carbonic acid diethyl ester; potassium hydroxide / ethanol / 4 h / 135 °C 1.2: 2 h / 170 - 190 °C 2.1: sodium hydride / tetrahydrofuran / 1 h / |Inert atmosphere; |Cooling with ice 2.2: 0 - 20 °C / |Inert atmosphere 3.1: diethylamino-sulfur trifluoride / dichloromethane / 96 h / -70 - 20 °C / |Inert atmosphere 4.1: hydrogen; palladium 10 on activated carbon / methanol / 20 °C View Scheme

1.1: sodium hydride / tetrahydrofuran / 1 h / |Inert atmosphere; |Cooling with ice 1.2: 0 - 20 °C / |Inert atmosphere 2.1: diethylamino-sulfur trifluoride / dichloromethane / 96 h / -70 - 20 °C / |Inert atmosphere 3.1: hydrogen; palladium 10 on activated carbon / methanol / 20 °C View Scheme

hydrogen bromide Heating;

hydrogen iodide Heating;

hydrogenchloride Heating;