Name the following compound. Give both an IUPAC and a common name if possible.

• CH₃CH=CHCHO

• A. IUPAC name: 2-butaldehyde
  Common name: not possible
• B. IUPAC name: but-2-enal
  Common name: not possible
• C. IUPAC name: but-2-enal
  Common name: propionaldehyde
• D. IUPAC name: 2-butaldehyde
  Common name: butyraldehyde

Answer: (B)