A new methodology is described herein which converts simple and readily accesible furan substrates into complex enantio-enriched carbocyclic skeletons through the implementation of a simple one-pot procedure. Singlet oxygen furan photoxygenation affords an enedione which then participates in an organocatalysed double-Michael reaction with an enal to furnish a cyclopentanone structure with up to four
A highly efficient one‐pot transformation of readily accessible furans into 4‐hydroxy‐2‐cyclopentenones in H2O, using singlet oxygen as oxidant, has been developed.