Access to chromone-3-carboxylic acid via silver mediated coupling of 4-hydroxy coumarin and enol ester was written by Mishra, Priyadarshini;Sepay, Nayim;Panda, Niranjan. And the article was included in Tetrahedron Letters in 2021.Application of 103-16-2 The following contents are mentioned in the article:
A silver-mediated aerobic approach to access 2-methyl-chromone-3-carboxylic acids from the reaction of 4-hydroxycoumarins and enol esters in the presence of base was presented. Mechanistic investigation suggested that the base induced Michael-type addition reaction of 4-hydroxycoumarins to the enol esters resulting the sequential ring opening and closing with the liberation of acetone were the key-steps for the overall transformation. Theor. calculation of energy of the intermediates by DFT supported the proposed reaction mechanism. This study involved multiple reactions and reactants, such as 4-Benzyloxyphenol (cas: 103-16-2Application of 103-16-2).
4-Benzyloxyphenol (cas: 103-16-2) belongs to ethers. Esters are also usually derived from carboxylic acids. It may also be obtained by reaction of acid anhydride or acid halides with alcohols or by the reaction of salts of carboxylic acids with alkyl halides. Esters contain a carbonyl center, which gives rise to 120° C–C–O and O–C–O angles. Unlike amides, esters are structurally flexible functional groups because rotation about the C–O–C bonds has a low barrier. Their flexibility and low polarity is manifested in their physical properties; they tend to be less rigid (lower melting point) and more volatile (lower boiling point) than the corresponding amides. Application of 103-16-2
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem