One-pot Synthesis of Some Novel 1,8-dioxooctahydroxanthenes Catalyzed by PVPP-OXA

Xanthenes have pharmacological properties such as antibacterial, antiviral, and antiinflammatory activities [1]. The synthesis of 1,8-dioxooctahydroxanthenes can becarried out in the presence of amberlyst-15 [2], Fe3+–montmorillonite [3], and SiO2-RSO3H [4]. In this research, a convenient and an efficient method was developed for the synthesis of some new 1,8-dioxooctahydroxanthene derivatives. The reaction proceeded via condensation of arylaldehydes with dimedon or 1,3-cyclohexadione in the presence of polyvinylpolypyrrolidone-supported oxalic acid (PVPP-OXA). In terms of reaction time and yields, the optimum results were obtained for the synthesis of 1,8-dioxooctahydroxanthenes in ethanol at room temperature. Clean methodologies, easy work-up procedure, high yield and simple preparation of the catalyst are some advantages of this work