Application： (S)-6-Oxo-2-piperidinecarboxylic acid can be used as a reactant to synthesize: Functionalized β-lactam N-heterocycles via carboxymethylproline synthase catalyzed cyclization reactions. Pro-(S)-C5 branched aza-amide bicycles as potential inhibitors for FK506-binding proteins. Ethyl (S)-2-(6-oxopiperidin-2-yl)acetate, which is reduced using LiBH4 to produce optically pure hydroxymethyl lactams.