Abstract A silver-mediated aerobic approach to access 2-methyl-chromone-3-carboxylic acid from the reaction of 4-hydroxy coumarin and enol ester in the presence of base has been presented. Mechanistic investigation suggests that… Click to show full abstract
Abstract A silver-mediated aerobic approach to access 2-methyl-chromone-3-carboxylic acid from the reaction of 4-hydroxy coumarin and enol ester in the presence of base has been presented. Mechanistic investigation suggests that the base induced Michael-type addition reaction of 4-hydroxy coumarin to the enol ester resulting the sequential ring opening and closing with the liberation of acetone are the key-steps for the overall transformation. Theoretical calculation of energy of the intermediates by DFT supports the proposed reaction mechanism.
               
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