Description General description 4-Pentenoyl chloride has been identified as a key impurity in 5-chlorovaleroyl chloride (5-CVC). 4-Pentenoyl chloride can be synthesized by reacting thionyl chloride and 4-pentenoic acid. Application 4-Pentenoyl chloride may be used in the preparation of: • D-pro-L-derived cyclic peptides • 4-pentenoylcobalt tricarbonyl • N-4-pentenoyl-L-cysteine methyl ester Packaging 5, 25 mL in glass bottle