Multi-component synthesis of xanthenediones by the lanthanum triflate catalyst

Xanthene derivatives possess agricultural, antibacterial, antiviral, anticoagulant, anticancer, diuretic, spasmolytic and anti-inflammatory properties which are also widely applied in photodynamic therapy [1]. Xanthenediones are important building blocks in a number of natural products and have been used as versatile synthons because of the inherent reactivity of the inbuilt pyranring [2,3]. Here, we wish to report our preliminary results on the synthesis of xanthenedione derivatives catalyzed by the lanthanum triflate catalyst from the reaction of dimedone and different aromatic aldehydes at 60 °C under solvent free conditions (Figure 1).