Ethyl 2,4-Dioxo-4-phenylbutyrate: A Versatile Intermediate for the Large-Scale Preparation of Enantiomerically Pure α-Hydroxy and α-Amino Acid Esters

Abstract

Starting from ethyl 2,4-dioxo-4-phenylbutyrate, both enantiomers of six enantiomerically pure α-hydroxy and α-amino acid esters (homophenylalanine derivatives) were prepared on >100 g scale. The key step involves a Pt-cinchona catalyzed enantioselective hydrogenation followed by enrichment via crystallization. All derivatives are commercially available.

Key words

hydrogenation - enantioselective synthesis - α-keto ester - α-hydroxy ester - homophenylalanine

References

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4

Exner, C.; Pfaltz, A.; Studer, M.; Blaser, H.-U. Adv. Synth. Catal., submitted.