New approach to the synthesis of substituted 7H-furo[3,2-b]pyran-7-ones based on 5-hydroxy-2-methyl-4H-pyran-4-one derivatives
Abstract
A convenient approach to the synthesis of the previously unknown 7H-furo[3,2-b]pyran-7-ones based on the intramolecular cyclization of carbonyl derivatives of 5-hydroxy-2-methyl-4H-pyran-4-one has been elaborated. Key intermediates in the synthesis of the target 7H-furo[3,2-b]pyran-7-ones are 3-hydroxy-6-methyl-2-(2-oxo-2-arylethyl)-4H-pyran-4-ones. They are formed as a result of multicomponent condensation of 5-hydroxy-2-methyl-4H-pyran-4-one with arylglyoxals and 4-methoxyaniline.