H6P2W18O62·18H2O: A green and reusable catalyst for one-pot synthesis of pyrano[4,3-b]pyrans in water

A convenient, efficient and environmentally benign procedure has been developed for the synthesis of pyrano[4,3-b]pyran derivatives via a one-pot, three-component reaction of 4-hydroxy-6-methylpyran-2-one, aldehydes and malononitrile in water using H6P2W18O62·18H2O as catalyst. Reusability of the catalyst and reaction media, short reaction times and easy isolation of products are some added advantages of the present methodology.

Graphical abstractA convenient, efficient and environmentally benign procedure has been developed for the synthesis of pyrano[4,3-b]pyran derivatives via a one-pot, three-component reaction of 4-hydroxy-6-methylpyran-2-one, aldehydes and malononitrile in water using H6P2W18O62·18H2O as catalyst. Reusability of the catalyst and reaction media, short reaction times and easy isolation of products are some added advantages of the present methodology.Figure optionsDownload full-size imageDownload as PowerPoint slide