1: N-[1-(S)-ethoxycarbonyl-3-phenylpropyl]-L-alanine N-carboxyanhydride With 1,1'-carbonyldiimidazole in tetrahydrofuran T=20°C; 1 h; 2: sodium (indan-2-yl)glycinate in tetrahydrofuran T=20°C; 3 h; 3: With hydrogenchloride in water pH=2 - 3; Product distribution / selectivity;