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.