A simple method for the synthesis of esters of 2-hydroxy-3-oxo-2,3-dihydrofuran-2-ylacetic acid

Abstract

Keywords: acetophenone, dibenzoylmethane, diethyl oxalate, ethyl acetate, ethyl esters of 2-hydroxy-3-oxo-2,3-dihydrofuran-2-ylacetic acids.2-Hydroxy-2,3-dihydrofuran-3-ones are successfully used in organic synthesis, especially for the preparation of biologically active compounds [1][2][3][4][5]. The known methods for the synthesis of 5-aryl-2-hydroxyfuran-3(2H)-ones generally include several stages and are not suitable for preparation [4,5]. We have developed a very simple and suitable one-step method for the synthesis of 2-hydroxy-3-oxo-2,3-dihydrofuran-2-ylacetate esters 1,2 by the reaction of ethyl acetate with diethyl oxalate and methyl ketones (for example, acetophenone or dibenzoylmethane) in the presence of sodium hydride with subsequent treatment of the mixture with hydrochloric acid: Me O EtO O O EtO OEt O R O H O O R O OEt 1) NaH 2) HCl -EtOH 1, 2 + + 1 R = H, 2 R = PhCOApart from compound 1, a secondary product -Z-2-hydroxy-4-oxo-4-phenyl-2-butenoic acid (benzoyltartaric acid) was isolated in 27% yield from the reaction mixture of ethyl acetate, diethyl oxalate, and acetophenone, which was identified by comparison with a known sample [6]. __________________________________________________________________________________________

4-Acetyl-2-hydroxy-2,5-dimethylfuran-3(2H)-one

“…The present method is superior in view of the synthesis of 4 than Wu's because of a very easy handling procedure using commercially-available simple materials [31] under mild conditions, such as room temperature in air, in addition to a synthetically acceptable yield, and the reaction using various 1,3-dicarbonyl derivatives are currently underway in our laboratory. A similar compound, ethyl 2-(2-hydroxy-3-oxo-5-phenyl-2,3-dihydrofuran-2-yl)acetate, is also known [32], which was prepared by condensation of ethyl acetate with diethyl oxalate and acetophenone.…”