An efficient approach to D-threo-3-hydroxyaspartic acid for the synthesis of novel L-threo-oxazolines as selective blockers of glutamate reversed uptake

An efficient, stereoselective synthetic strategy to D-threo-3- hydroxyaspartic acid was developed. Starting from L-(2S,3S)-N-benzoyl-3- hydroxyaspartic acid dimethyl ester by a Deoxo-fluor-catalyzed cyclization reaction, an inversion of configuration at the β-center (erythro isomer), was observed. A base-induced epimerization reaction led to the D-trans-isomer, which was hydrolyzed to give D-threo-3-hydroxyaspartic acid with excellent stereoselectivity and overall yield. Starting from D-threo-3-hydroxyaspartic acid, L-threo-oxazolines can be stereoselectively synthesized. © 2004 Elsevier Ltd. All rights reserved.