1: With sodium hydroxide in water T=20°C; 0.5 h; 2: With hydrogenchloride in water T=0 - 5°C; pH=2 - 3; 2 h; 3: With acetic anhydride in toluene T=20°C; 12 h; Heating / reflux;

1: pyrrolidin-2-one With sodium hydride in tetrahydrofuran T=20°C; 0.75 h; 2: (S)-2-bromobutanoic acid in tetrahydrofuran T=20°C; 16 h;

lithium hydroxide; dihydrogen peroxide in tetrahydrofuran T=0°C; 7 h;

1.1: N,N'-dicyclohexylcarbodiimide / CH2Cl2 / 0.33 h / 0 °C 1.2: 25 percent / 4-(dimethylamino)pyridine / CH2Cl2 / 16 h / -78 °C 2.1: 141 mg / LiOH*H2O; H2O2 / tetrahydrofuran / 7 h / 0 °C View Scheme

1: With chloroformic acid ethyl ester; triethylamine in tetrahydrofuran T=0°C; 0.5 h; 2: With ammonium hydroxide in tetrahydrofuran; water T=20°C; 16 h;