Abstract
Here, we report a novel, green, simple, low-cost, and rapid methodology for the high-yield production of pyran-2,4-dione scaffolds under microwave irradiation. Regio- and stereoselective conversions of beta-diketone systems into beta-enaminones were achieved using 18 primary amines and four amino acid esters. Microwave-assisted further cyclization of 3-(beta-substitutedvinyl)-6-phenyl-pyran-2,4-dione into 3-benzoyl-4,7-diphenyl-2H,5H-pyrano[4,3-b]pyran-2,5-dione via reaction with ethyl benzoyl acetate. (C) 2020 Elsevier Ltd. All rights reserved.