Intermolecular Tandem Addition/Esterification Reaction of Alkenes with Malonates Leading to gamma-Lactones Mediated by Molecular Iodine under Visible Light Irradiation

摘要

The iodine-mediated intermolecular CC bond-forming/esterification reaction of various alkenes including alpha-olefins with malonates under irradiation using a compact fluorescent lamp has been developed to synthesize gamma-lactones in moderate to excellent yields. The method developed in this research shows broad substrate scope and moderate diastereoselectivity and constructs valuable polyfunctionalized gamma-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 CC bond-forming reaction.gamma