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ABSTRACT The Curtin–Hammett principle, widely recognized in thermal reactions, has been extended to photosensitization processes in this study, providing new insights into the reactivity of photogenerated singlet oxygen (¹O₂) with phenol and phenolate anion species. Here, we explore mechanistic and Curtin–Hammett studies of the equilibrium between the phenol and phenolate anion forms of a prenylated natural product, prenylphloroglucinol. This study uses density functional theory (DFT) to examine phenol and phenolate anion‐quenching pathways of¹O₂showing distinct pathways for each form. In the phenolate anion,¹O₂is quenched to form a peroxy anion. In contrast, in the phenol form,¹O₂leads to a potent epoxidizing agent in a seemingly pro‐oxidant path. Aniso‐hydroperoxyhydrofuran intermediate is proposed to be key in the epoxidation. Meanwhile, the phenolate anion cyclizes and protonates forming a comparatively benign hydroperoxyhydrofuran species. The phloroglucinol is next to the C‐prenyated group directs the reaction pathway towards the formation of a dihydrobenzofuran, deviating from the conventional¹O₂“ene” reaction mechanism and the production of allylic hydroperoxides typically observed in trisubstituted alkenes.