A stereoselective synthesis of α-deuterium-labelled (S)-α-amino acids
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An atom-efficient and stereoselective synthesis has been developed for the preparation of α-2H-labelled (S)-α-amino acids, starting from a novel chiral diketopiperazine scaffold. Efficient mono-alkylation of the chiral template afforded the (S)-substituted adducts with the nature of the electrophile significantly effecting the stereochemical outcome. Subsequent alkylation was totally selective producing the 1,4-cis adduct as the sole diastereoisomer. The deprotection was carried out using cerium ammonium nitrate followed by acid hydrolysis affording the enantipure α-amino acids.
Keywords(S)-Deuterated-α-amino acids Diketopiperazine Asymmetric synthesis
We express our gratitude to Sustainable Energy Ireland, administered by the Irish Research Council for Science, Engineering and Technology (IRCSET) for funding Elaine O’Reilly. We would also like to acknowledge the facilities of the Centre for Synthesis and Chemical Biology (CSCB), funded by the Higher Education Authorities Programme for Research in Third-Level Institutions (PRTLIs). We are grateful to Prof. Patrick Guiry for the use of his Perkin-Elmer 241 polarimeter.
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