Photoinduced deacylative epoxidation of ketone derivatives with allylic peroxides.

Epoxide compounds represent a privileged scaffold with diverse applications in organic synthesis, pharmaceuticals, agrochemicals, and materials science. However, the available routes to obtain such high-value structures from feedstocks, such as ketones, remain less developed. In this work, we report an alternative deacylative epoxidation of ketones using allylic peroxides to produce fused epoxides via the photoinduced radical cyclization of ketone-derived pro-aromatic dihydroquinazolinones. This system operates under very mild conditions and showcases a broad substrate scope with excellent functional group tolerance (over 50 examples). Its gram-scale preparation and late-stage transformations emphasize its potential in drug discovery. A possible mechanism has been proposed based on mechanistic studies.