Claisen Rearrangement for the Synthesis of γ,δ-Unsaturated Amino Acid Esters

Keywords

γ,δ-unsaturated amino acids - Claisen rearrangement - ZnCl₂

Significance

Unnatural amino acids, especially γ,δ-unsaturated amino acids, play an important role in the peptide-based drug discovery industry. In this study, the authors developed the Claisen rearrangement of N-protected amino acid esters of enynols for the synthesis of γ,δ-unsaturated amino acid esters.

Comment

Lithium base-mediated chemoselective Claisen rearrangement of N-protected amino acid esters of enynols proceeded smoothly to afford the corresponding γ,δ-unsaturated amino acids in good yields with excellent chemoselectivity. This reaction is practically simple and proceeds cleanly under mild reaction conditions.