[Na].[C:2]([O:9][CH2:10][CH3:11])(=[O:8])[C:3]([O:5]CC)=O.[CH3:12][C:13]1[CH:18]=[C:17]([CH3:19])[CH:16]=[C:15]([CH3:20])[C:14]=1[C:21](=[O:25])[CH2:22][CH2:23][CH3:24]>CCO>[CH2:23]([CH:22]([C:21](=[O:25])[C:14]1[C:15]([CH3:20])=[CH:16][C:17]([CH3:19])=[CH:18][C:13]=1[CH3:12])[C:3](=[O:5])[C:2]([O:9][CH2:10][CH3:11])=[O:8])[CH3:24]Sodium (1.0 g, 42.1 mmol, spheres was cautiously added to 25 mL of absolute EtOH with stirring. After the sodium had dissolved, diethyl oxalate (6.0 g, 42.1 mmol) was added dropwise to the resulting solution at 0° C., followed by addition of a solution of 2′,4′,6′-trimethylbutyrophenone (8 g, 42.1 mmol) in 5 mL of absolute EtOH. The reaction zmixture was slowly warmed to 50° C. and stirred overnight. The solvent was then evaporated. The resulting residue was washed with hexane, diluted with water, acidified with 1 N HCl, and then extracted with ether. The extracts were washed with brine, dried over Na2SO4 and concentrated to give 6.5 g of an oil which was used in the next reaction without farther purification.
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