1: With water; lithium hydroxide hydrate in ethanol 1 h; Heating; 2: With potassium hydrogensulfate in water pH=3 - 4;

trifluoroacetic acid in dichloromethane T=20°C; 17 h;

1.1: sodium tetrahydroborate; cobalt(II) chloride / methanol / 24 h / 0 - 20 °C / |Inert atmosphere 1.2: 3 h / |Inert atmosphere 2.1: Lawesson's reagent / tetrahydrofuran / 17 h / 20 °C / |Inert atmosphere 3.1: hydrogen / water; tetrahydrofuran / 2 h / 20 °C / |Inert atmosphere 4.1: sodium hydroxide / water / 16 h / 20 °C / pH 8 - 10 5.1: trifluoroacetic acid / dichloromethane / 17 h / 20 °C View Scheme

1: Lawesson's reagent / tetrahydrofuran / 17 h / 20 °C / |Inert atmosphere 2: hydrogen / water; tetrahydrofuran / 2 h / 20 °C / |Inert atmosphere 3: sodium hydroxide / water / 16 h / 20 °C / pH 8 - 10 4: trifluoroacetic acid / dichloromethane / 17 h / 20 °C View Scheme

1: sodium hydroxide / water / 16 h / 20 °C / pH 8 - 10 2: trifluoroacetic acid / dichloromethane / 17 h / 20 °C View Scheme

1: hydrogen / water; tetrahydrofuran / 2 h / 20 °C / |Inert atmosphere 2: sodium hydroxide / water / 16 h / 20 °C / pH 8 - 10 3: trifluoroacetic acid / dichloromethane / 17 h / 20 °C View Scheme

palladium 10 on activated carbon; hydrogen in methanol T=20°C; 1 h;

1: With diphenyl phosphoryl azide; triethylamine 1 h; HeatingReflux; 2: 24 h; sealed tubeHeating;