ammonium hydroxide; ethane-1,2-dial in methanol; dichloromethane; water T=20°C;

ammonia in methanol; water T=10°C; 22 h;

1: 1-(tert-butoxycarbonyl)-L-proline With ammonia in methanol T=20°C; 0.5 h; 2: ethane-1,2-dial T=20 - 60°C; 16 h;

1: N-(tert-butyloxycarbonyl)-L-prolinol With 2,2,6,6-tetramethyl-1-piperidinyloxy, free radical; potassium hydrogencarbonate; potassium bromide in dichloromethane; water T=0 - 5°C; 0.166667 h; Inert atmosphere; 2: With sodium hypochlorite in dichloromethane; water T=0 - 5°C; 1 h; Inert atmosphere; 3: ethane-1,2-dial With ammonium hydroxide in acetonitrile T=0 - 20°C; 19 h; Inert atmosphere;

1: sodium hydrogencarbonate; sodium hypochlorite; 2,2,6,6-tetramethyl-piperidine 1-oxide; sodium bromide / dichloromethane / 1 h / 0 °C 2: ammonia / water; methanol / 22 h / 10 °C View Scheme

N-bromosuccinmide in dichloromethane T=-10°C; 3 h;

1: With iodine; sodium hydroxide in chloroform; water T=20°C; 15 h; 2: With sodium sulfite in ethanol; water 40 h; Reflux;