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

• Published in: Angewandte Chemie International Edition 2019-11, Vol.58 (45), p.16115-16118
• Main Authors: Petti, Alessia, Leech, Matthew C., Garcia, Anthony D., Goodall, Iain C. A., Dobbs, Adrian P., Lam, Kevin
• Format: Article
• Language: English
• Subjects: Electrochemistry; electrosynthesis; green chemistry; Lactones; Organic chemistry; radical cyclisation; Radicals; Salts
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201909922

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. Clean electricity: A new electrochemical method generates 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.