An efficient approach for the synthesis of 3-(polyfluoroacyl)pyruvaldehydes dimethyl acetals (1,1-dimethoxy-4-polyfluoroalkyl-butan-2,4-dions) from 1,1-dimethoxyacetone and polyfluorinated carboxylic acid esters has been developed. The procedure includes the Claisen type condensation of the starting materials by means of calcium hydride in methanol, followed by isolation of copper complexes of the corresponding diketones and their destroying with disodium EDTA. A simple synthesis of 5(3)-(polyfluoroalkyl)-1H-pyrazole-3(5)-carbaldehydes and their acetals is also presented.