Springer Online Journal Archives 1860-2000
Chemistry and Pharmacology
Abstract β-Keto esters derived from dipeptides areprepared by application of common methodologiesemployed for the synthesis of amino acid-derivedβ-keto esters; however, epimerization of theC-terminal residue occurred to different extentsdepending on the method. In imidazolide activateddipeptides, this epimerization is due to the CDIactivation step and to the configurational instabilityof the intermediate imidazolides in different reactionmedia. Regarding yield and diastereomeric purity, themethod of choice proved to be the reaction ofdipeptide-derived imidazolide with the potassium saltof malonic half esters in the presence of MgCl2.
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