[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 mixture 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 further purification.
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