Clay catalysis: solventless condensation of 3-coumaranones with 1,2--dicarbonyl compounds under microwave irradiation. Synthesis of new acylaurones.

Abstract:

Aurones are natural bioactive dyes found in plants, many of them are biologically actives. Aurones can be obtained by the condensation of 3-coumaranones (benzofuran-3(2H)-one derivatives) with aldehydes. In this reaction ketones generally do not react. We reported herein that 1,2-dicarbonyl compounds condense with 3-coumarones, without solvent under microwave irradiation with clay as catalyst. Novel acylaurones were prepared in good yields, the more stable E-isomer was formed stereoselectively. The biologically properties of the new acylaurones will be tested.