Variability of the Transformations of 4-Hydroxy-6-methyl-2H-pyran-2-one under Modified Biginelli Reaction Conditions

Abstract

A modified version of the three-component Biginelli reaction of 4-hydroxy-6-methyl-2H-pyran-2-one with aromatic aldehydes in urea under conventional heating and microwave activation has been studied. Depending on the order of addition of the reactants, substituted (pyrano)chromenones, 10-amino-4a-hydroxydihydropyranochromen- 2-one, and 3-[amino(phenyl)methyl]-4-hydroxypyran-2-one were obtained.