Regioselective synthesis of Dihydroxanthones and Xanthones through a Tandem process

Xanthones and dihydroxanthones are important mycotoxin-related compounds present in many plants, fungi and lichens, and have been demonstrated to be able to interact with different biological targets. But their synthesis are tedious and through a multistep procedures. We have developed a one pot application for the synthesis of this kind of products with up to 4 diversification structural positions.

Starting from easily available 3-carbonylchromones¹, isocyanides and different dienophiles we have teamed up to obtain Xanthones and dihydroxanthones in a one pot tandem procedure through a [4 + 1]−[4 + 2] cycloaddition leading these complex structures. This synthesis efficiently affords a variety of both monomeric and dimeric polysubstituted dihydroxanthones structurally similar to bioactive ergochromes.²

                (1)          Bornadiego, A.; Diaz, J.; Marcos, C. F. Adv Synth Catal 2014, 356, 718.

                (2)          Bornadiego, A.; Diaz, J.; Marcos, C. F. J Org Chem 2015, 80, 6165.