Synthesis of Unusual Aromatic L-Amino Acids by Asymmetric Hydrogenation of Cyclic Dehydrodipeptides

Article abstract of DOI:10.1246/bcsj.59.323

To prepare L-Tyr(Me) and L-Amp (L-2-amino-5-(p-methoxyphenyl)pentanoic acid), their precursors cyclo(-ΔTyr(Me)-L-Ala-) and cyclo(-ΔAmp-L-Ala-) were hydrogenated in N,N-dimethylformamide.The content of LL isomers in the hydrogenated products was over 94percent.Mild acid hydrolysis of the hydrogenated products and subsequent recrystallization gave pure L-Tyr(Me) and L-Amp.