Scalable Diastereoselective Electrosynthesis of Spiro[benzofuran-2,2'-furan]-3-ones.

Spirobenzofuran scaffolds, because of their three-dimensional structure, are incorporated into several valuable natural products and drug candidate molecules. Herein, with the assistance of electrosynthesis, we introduce a novel electrochemical approach for achieving spirobenzofurans in a user-friendly and operationally simple undivided cell setup under constant current. This metal-catalyst-free electrochemical procedure afforded spiro[benzofuran-2,2'-furan]-3-ones with high diastereoselectivity. Compatibility with gram-scale synthesis along with the convenient accessibility of reaction instruments and starting materials collectively raised the importance of this protocol compared to previous challenging methods. Furthermore, mechanistic cognizance of this reaction is obtained by the investigation of the cyclic voltammetry spectra of reactants.