AbstractThe iodine‐mediated intermolecular C−C bond‐forming/esterification reaction of various alkenes including α‐olefins with malonates under irradiation using a compact fluorescent lamp has been developed to synthesize γ‐lactones in moderate to excellent yields. The method developed in this research shows broad substrate scope and moderate diastereoselectivity and constructs valuable polyfunctionalized γ‐lactones. Furthermore, the developed methodology was comprehensively studied by performing several control experiments, radical trapping, and radical clock experiments. These experiments showed that sequential iodination by an iodine radical is triggered for the following C−C bond‐forming reaction.γmagnified image