1: (R)-N-Boc-cyclohexyl-glycine With chloroformic acid ethyl ester; triethylamine in tetrahydrofuran T=0°C; 1 h; 2: diazomethane in tetrahydrofuran; diethyl ether T=0 - 20°C; 3: With hydrogenchloride; sodium hydroxide; silver trifluoroacetate; triethylamine more than 3 stages;