The convenient one-pot method for phosphoryloxylactonization of alkenoic acids was reported:when(diacetoxyiodo)benzene, various 4-pentenoic acids and phosphates were mixed in CH_3CN at room temperature,phosphoryloxylactones were obtained in good to excellent yields in short times,some had two diastereoisomers. The convenient one-pot method for phosphoryloxylactonization of alkenoic acids was reported: when (diacetoxyiodo) benzene, various 4-pentenoic acids and phosphates were mixed in CH_3CN at room temperature, phosphoryloxylactones were obtained in good to excellent yields in short times, some had two diastereoisomers.