Formation of fluoroalkyl-containing pyran-4-one in the reaction of lithium 4,4,4-trifluoro-1-phenylbutane-1,3-dionate with oxalyl chloride

(1 g, 4.5 mmol)and oxalyl chloride (0.4 mL, 4.5 mmol) in anhydrous toluene(25 mL) was refluxed for 3 h. After completion of the reaction,the precipitate was filtered, and the filtrate was concentratedand cooled. The precipitate that formed was filtered off andrecrystallized from diethyl ether. Compound