Decatungstate-photoinitiated skeletal editing of cyclic ketones by ring expansion/acylation

Six-membered and seven-membered carbocycles are prevalent in nature due to their low ring strain and structural stability. In this work, we introduce a novel photocatalytic skeletal editing strategy for Dowd-Beckwith ring expansion acylation, leveraging tetrabutylammonium decatungstate (TBADT) as a hydrogen atom transfer (HAT) photocatalyst. This innovative approach enables the efficient synthesis of a diverse range of six- and seven-membered cyclic ketones under mild conditions, offering key advantages including environmental sustainability, high atom and step economy, good functional group tolerance, and the potential for extensive downstream functionalization. The versatility of this strategy is further demonstrated by its successful application in the post-synthetic modification of complex pharmaceutical intermediates and its scalability via continuous-flow technology, underscoring its broad utility in synthetic chemistry and pharmaceutical development.