The substrate 4-hydroxy tiglic acid (1), which has low singlet oxygen reactivity, is converted to the 1,2-hydroperoxyalcohol 2 by photooxygenation in deuterated solvents and used for subsequent BF₃-catalyzed peroxyacetalizations with acyclic and cyclic ketones. This route enables the synthesis of water-soluble trioxanes that are versatile building blocks for further functionalization, e.g. ester and amide formation.