1: N-(tert-butoxycarbonyl)phenylalanine With 2,4,6-trimethyl-pyridine; dicyclohexyl-carbodiimide in tetrachloromethane T=-20°C; 1 h; Inert atmosphere; 2: tert-butyl alcohol With (S)-(+)-1-tert-butyldiphenylsilyloxy-3-(3'-methyl-3'H-imidazol-4'-yl)-2-(2'',4'',6''-triisopropylbenzenesulfonylamino)propane in tetrachloromethane T=-20°C; 20 h; Inert atmosphere; 3: With hydrogenchloride; water in tetrachloromethane Inert atmosphere; optical yield given as percent eeenantioselective reaction;
