Succinaldehyde or Butanedial is an organic compound with the formula (C2H4)(CHO)2. It is a colorless viscous liquid. Typical of some other saturated dialdehydes, succinaldehyde is handled as the hydrates or methanol-derived acetal. It is a precursor to tropinone. Succinaldehyde can be used as a crosslinking agent for proteins, but it is less widely used than the related dialdehyde glutaraldehyde.