CAS 41888-21-5 appears in our catalog under these names: 2-Oxopiperidine-3-carboxylic acid, 95%, 2–Oxo–3–piperidinecarboxylic acid, 2-Oxopiperidine-3-carboxylic acid 98%, 2-Oxopiperidine-3-carboxylic acid, 98%, 98%, 2-Oxo-piperidine-3-carboxylic acid, 95%. Offered by: Combi-blocks, GLPBio, Ambeed, Chemat, Fluorochem. Available pack sizes: 250mg, 5g, 1g, 100mg, 10g.