1: (3aS,4R,6S,6aR)-6-hydroxy-2,2-dimethyltetrahydro-3aH-cyclopenta[d][1,3]dioxol-4-aminium (2S)-2-[(tert-butoxycarbonyl)amino]-3-phenylpropanoate With hydrogenchloride in ethyl acetate T=5°C; pH=1 - 2; 0.416667 h; 2: benzyl chloroformate With potassium carbonate in water; isobutyl methylketone T=20 - 30°C; 0.666667 h;