* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.
With sodium hydride; In toluene; mineral oil; for 5h;Reflux;
General procedure: To a solution of ketone (20 mmol) in toluene (80 mL) was added dimethyl carbonate (60 mmol) and NaH (40 mmol, 60%). The reaction mixture was refluxed for 5 h until TLC indicated the total consumption of the ketone. After cooling, the reaction mixture was poured into ice-water (100 mL), acidified with 3 M HCl to pH 2-3 and extracted with EtOAc (100 mL x3). The combined organic layer was dried over Na2SO4 and evaporated under reduced pressure. The residue was purified by flash column chromatography (petroleum ether /EtOAc = 10/1) to afford the desired compound.
Example 39 Methyl 2-Furanoylacetate beta-ketoester: 20 equivalents, reaction time: 8 hours. Yield: 61 mg, recovery: 66%. The product is the ester compound represented by the following structural formula, and its 1H-NMR (500 MHz, CDCl3) is the same as that of the compound in Example 19.
11
[ 615-06-5 ]
[ 5396-64-5 ]
(4S,5S)-5-(3,4-Dimethoxy-phenyl)-4,5-dihydro-[2,2']bifuranyl-3,4-dicarboxylic acid dimethyl ester[ No CAS ]