sodium tetrahydroborate; (2S)-2-amino-3,3-dimethylbutanoic acid in tetrahydrofuran T=0°C; 1 h; asymmetric reduction with the ragents prepared from NaBH4 and optically active α-amino acids; other reagents, effect of temperature; Product distribution;

hydrogenchloride; sodium hydroxide in methanol; water

sodium hydroxide; water in methanol 2 h; Ambient temperature;

1: 84.1 percent / DMSO, Py / 24 h / Ambient temperature 2: 86.7 percent / NaOH, H2O / methanol / 2 h / Ambient temperature View Scheme