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 -(2 S ,3 S )- 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.