diphenyl phosphoryl azide; triethylamine in methanol; n-heptane; ethyl acetate; tert-butyl alcohol T=25°C; 24 h; Reflux;

1.1: water / tetrahydrofuran / 72 h / 25 °C 1.2: pH 0 2.1: triethylamine; diphenyl phosphoryl azide / ethyl acetate; n-heptane; tert-butyl alcohol; methanol / 24 h / 25 °C / Reflux View Scheme

1.1: hydrogenchloride / methanol / 18 h / Reflux 2.1: dichloromethane / 3 h / 25 °C / Cooling with ice 3.1: potassium hydroxide; copper (II) acetate monohydrate / ethanol / 18 h / 90 °C / Inert atmosphere 4.1: water / tetrahydrofuran / 72 h / 25 °C 4.2: pH 0 5.1: triethylamine; diphenyl phosphoryl azide / ethyl acetate; n-heptane; tert-butyl alcohol; methanol / 24 h / 25 °C / Reflux View Scheme

1.1: dichloromethane / 3 h / 25 °C / Cooling with ice 2.1: potassium hydroxide; copper (II) acetate monohydrate / ethanol / 18 h / 90 °C / Inert atmosphere 3.1: water / tetrahydrofuran / 72 h / 25 °C 3.2: pH 0 4.1: triethylamine; diphenyl phosphoryl azide / ethyl acetate; n-heptane; tert-butyl alcohol; methanol / 24 h / 25 °C / Reflux View Scheme