Synthesis of fluorescent enone derived α-amino acids

The development of a facile and general method for the preparation of enone derived α-amino acids is described. The key step involves a Horner–Wadsworth–Emmons reaction between an aspartic acid derived β-keto phosphonate ester and a range of aldehydes resulting in the formation of highly functionalised α-amino acids in good yields. An efficient two-stage deprotection process using mild conditions was developed to give the parent α-amino acids. Application of this methodology has produced a novel fluorescent α-amino acid that has potential as a biological marker.