Opticallyactive and racemic isomers of aspartic acid (1) were transformed into the corresponding N-trifluoroacetyl-5-bromo-4-oxonorvaline methyl esters (6, R = Me) and N-trifluoroacetyl-3-formylalanine methyl esters 13, which were used as starting compounds in the synthesis of β-heteroaryl substituted-α-amino acids.