Synthesis of γ‑Lactones by TBAI-Promoted Intermolecular Carboesterification of Carboxylic Acids with Alkenes and Alcohols

A novel tetrabutylammonium iodide (TBAI)-promoted three-component
reaction of carboxylic acid with alkene and alcohol has been developed,
which represents facile and straightforward access to polysubstituted
γ-lactone skeletons in moderate-to-good yields. This methodology
is distinguished by the use of a commercial catalyst and readily available
starting materials, wide substrate scope, and operational simplicity.
Mechanistic studies suggested that this transformation went through
a radical process.