Economical, Green, and Safe Route Towards Substituted Lactones by Anodic Generation of Oxycarbonyl Radicals

Abstract

A new electrochemical methodology has been developed for the generation of oxycarbonyl radicals under mild and green conditions from readily available hemioxalate salts. Mono- and multi-functionalised γ-butyrolactones were synthesised through exo-cyclisation of these oxycarbonyl radicals with an alkene, followed by the sp³ -sp³ capture of the newly formed carbon-centred radical. The synthesis of functionalised valerolactone derivatives was also achieved, demonstrating the versatility of the newly developed methodology. This represents a viable synthetic route towards pharmaceutically important fragments and further demonstrates the practicality of electrosynthesis as a green and economical method to activate small organic molecules.

Keywords: electrochemistry; electrosynthesis; green chemistry; lactones; radical cyclisation.