1: (S)-(-)-N-(2-Ethyl-6-methyl-phenyl)-alanin With sodium tetrahydroborate; sulfuric acid in tetrahydrofuran T=20°C; 2: chloroacetyl chloride With sodium carbonate in benzene T=20°C; 3 h; 3: 2,2-dimethoxy-propane With toluene-4-sulfonic acid in methanol 36 h; Heating; Title compound not separated from byproducts;

1: 104 g / BH3*S(CH3)2 / tetrahydrofuran / 20 h / Heating 2: Na2CO3 / benzene / 3 h / Ambient temperature 3: p-TsOH / methanol / 36 h / Heating View Scheme

1: (S)-(-)-N-(2-Ethyl-6-methyl-phenyl)-alanin With sodium tetrahydroborate; sulfuric acid in tetrahydrofuran T=20°C; 2: chloroacetyl chloride With sodium carbonate in benzene T=20°C; 3 h; 3: 2,2-dimethoxy-propane With toluene-4-sulfonic acid in methanol 36 h; Heating; Title compound not separated from byproducts;