An efficient synthesis of γ-amino β-ketoester by cross-Claisen condensation with α-amino acid derivatives

Cross-ester condensation between N-protected amino acid ester and the lithium enolate prepared from alkyl acetate gave the corresponding β-ketoester in high yield without the formation of the tertiary alcohol that is commonly seen as by-product. This interesting reaction is applicable to the amino acid derivatives with suitable N-protecting groups, which can help to stabilize the reaction intermediates.