A stereoselective synthesis of α-deuterium-labelled (S)-α-amino acids

An atom-efficient and stereoselective synthesis has been developed for the preparation of α-H-labelled (S)-α-amino acids, starting from a novel chiral diketopi-perazine 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. © Springer-Verlag 2010.