Novel isocyanide-based three-component synthesis of substituted 9Hfuro[ 2,3-f]chromene-8,9-dicarboxylates in water

Three-component reaction of 1-(6-hydroxy-2-isopropenyl-1-benzofuran-yl)-1-ethanone, dialkyl acetylenedicarboxylates and isocyanides in water was described as efficient and green synthetic procedure for preparation of 9Hfuro[ 2,3-f]chromene-8,9-dicarboxylates in excellent yield. In these reactions, 1-(6-hydroxy-2-isopropenyl-1-benzofuranyl)- 1-ethanone was extracted from rhizomes of Petasites hybridus from northern Iran. The structure of this compound was determined by 1H, 13C-NMR and IR spectroscopy and confirmed by X-ray diffraction analysis. This procedure provides rapid access to novel and diversely substituted 9H-furo[2,3-f]chromene-8,9-dicarboxylate derivatives.