1: in dichloromethane T=-15 - 35°C; 2: With sodium hydroxide; water in ethyl acetate pH=4.2 - 4.5;

1: N-[1(S)-ethoxycarbonyl-1-butyl]-(S)-alanyl chloride hydrochloride With 1H-imidazole in dichloromethane T=10 - 15°C; 1 h; 2: (2S,3aS,7aS)-octahydroindole-2-carboxylic acid trimethylsilyl ester in dichloromethane T=10°C; 3 h; 3: tert-butylamine in dichloromethane T=10 - 40°C; 1 h; Product distribution / selectivity;