Electrosynthesis of γ-Butyrolactones by Dehydrogenative (3+2) Annulation.

The synthetic research for building γ-butyrolactones is being developed due to the high value of lactone skeletons, commonly found in natural products, functional molecules, bioactive agents and pharmaceuticals. However, reported synthetic methods, including harsh conditions, reliance on volatile activating reagents, and using noble metals, remain challenging. In this work, we present an electro-oxidative (3+2) annulation of alkenes with 1,3-diesters, offering an efficient route to γ-butyrolactones. This approach eliminates the need for external oxidants or bases and substrate pre-activation. Mechanistic studies suggest that ferrocene acts as a mediator to activate 1,3-diesters.