An atom-efficient and stereoselective synthesis has been developed for the preparation of a-2H-labelled(S)-a-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 a-amino acids.
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Higher Education Authority
Irish Research Council for Science, Engineering and Technology