To obtain the subject new compound useful as an intermediate for antiferroelectric liquid crystal compounds, or as a building blocking agent capable of introducing various functional groups into compounds to be used as medicines or agrochemicals.

This new compound is expressed by the formula (m is 3-6), e.g. (S)-1-hydroxy-2,2,2-trifluoroethyl-4-ethoxybutyl ketone. The compound of the formula is obtained by reaction between (S)-N-(2-hydroxy-3,3,3- trifluoropropionyl)pyrrolidine and a compound of the formula C2H5O(CH2)mMgBr in an organic solvent such as diethyl ether, tetrahydrofuran or diglyme followed by the hydrolysis of the reaction product with a mineral, acid such as hydrochloric acid, sulfuric acid or nitric acid.