tert-butyl 4-formyl-4-methylpiperidine-1-carboxylate; CAS No.: 189442-92-0; tert-Butyl 4-formyl-4-methylpiperidine-1-carboxylate exemplifies ChemShuttle s aldehyde-functionalized piperidines for reductive amination. As a chemical synthesis company, they stabilize aldehydes as hydrates to prevent polymerization during storage.