The synthesis of chiral 3-oxo-6-[(phenylmethoxy)-carbonyl]-2-piperazineacetic acid esters designed for the presentation of an aspartic acid side chain. A subsequent novel Friedel Crafts reaction

Article abstract of DOI:10.1016/S0040-4039(00)60843-2

The syntheses of (2S, 6R)-, and (2S, 6S)-3-oxo-6-[(phenylmethoxy)carbonyl]-2-piperazineacetic acid methyl esters from L- or D-serine and dimethyl-D-malate are described. Acylation of the (2S, 6S) isomer with 3-methoxyphenylacetyl chloride, hydrogenolysis of the benzyl ester, followed by treatment with oxalyl chloride then aluminum chloride led to an unexpected tricyclic product into which a C₂O₂ unit had been incorporated.