Abstract The tosyl ester 2 of tetraethyl 1-acetamido-4-hydroxybutane-1, 1, 3, 3- tetracarboxylate gave 4-methylene glutammic acid in 90% yield by refluxing with concentrated HC1. Treatment of 2 with NaOEt, then with refluxing concentrated HC1 gave a 54% yield of cis and trans-pyrrolidine-2, 4-dicarboxylic acids 4 and 5, separated by anion exchange chromatography An analytical resolution of 4 and 5 enantiomers by chiral ...
