ABSTRACT

α,β-Unsaturated amino acids with free α-amino groups are not stable; N-acylated α,β-unsaturated amino acids are stable compounds. The α,β-unsaturated amino acids listed in this table are present in natural products in which they are stabilized by peptide bond formation. The addition of mercaptans to α,β-unsaturated amino acids and the reversible conversion to keto acids and amides are of biological significance.1,2,11