Light promoted synthesis of 1,8-dioxooctahydroxanthenes using sulphated tin oxide as solid support catalyst

In the past few years multi component reactions have captured the attention of synthetic chemists as they provide easy access to diverse complex organic molecules through carbon - carbon and carbon - heteroatom bond formations in tandem manner with simple easy to carry out reaction conditions in short time. 1,8-dioxo-octahydroxanthene is a significant class of oxygen containing heterocycle in which a phenyl substituted pyran ring is fused on either side with two cyclohexanone rings and this unit constitutes in a number of natural products with wide range of therapeutic and pharmacological properties. The present paper describes house hold 100 watt bulb promoted multicomponent reaction between dimedone and various substituted cinnamaldehydes/ substituted benzaldehydes to afford the corresponding 1,8-dioxo-octahydroxanthene derivatives using sulphated tinoxide as solid supported catalyst. This green procedure using heterogenous catalyst and light as source of energy provides facile access to a variety of 1,8-dioxo- octahydroxanthene derivatives in good to excellent yield.