Tetramic acid was synthesized from Cbz-protected glycine and Meldrum's acid. It was then used as a starting compound for the preparation of tetramic acid derivatives, starting with Michael addition of trans-β-nitrostyrene. Two different organocatalysts were used in this step: a chiral and an achiral one. The products of Michael addition were then alkylated with benzyl bromide and the final products were obtained. One of them was formed as a racemic mixture and the other one was enantiomerically enriched. The enantiomeric excess of the latter one was determined with the help of HPLC.
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