[CH3:1][C:2]([C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1)([CH3:6])[CH2:3][Mg]Cl.[F:13][C:14]([F:23])([F:22])[C:15](=[O:21])[C:16]([O:18][CH2:19][CH3:20])=[O:17]>C(OCC)C.C1COCC1>[CH2:19]([O:18][C:16](=[O:17])[C:15]([OH:21])([C:14]([F:13])([F:22])[F:23])[CH2:3][C:2]([CH3:1])([C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1)[CH3:6])[CH3:20]To a room temperature solution of 45 mL (22.5 mmol) of a 0.5 M solution of 2-methyl-2-phenylpropylmagnesium chloride in diethyl ether was added 38 g (22.5 mmol) of ethyl trifluoropyruvate in 10 mL of anhydrous THF. The reaction became slightly warm to the touch and a white precipitate quickly developed. After 2 hours, the reaction was diluted with diethyl ether and quenched with 1 N aqueous HCl. The aqueous layer was separated and extracted with ether. The combined organic layers were dried over magnesium sulfate, filtered, and concentrated in vacuo to afford a brown oil. Chromatography on silica gel eluting with hexanes-EtOAc (98:2), afforded the title compound as a clear, colorless oil (4.6 g, 67%).
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