PURPOSE: To prepare 5-chloro-2-pentanone advantageously by ketalizing a levulinic ester with ethylene glycol, subjecting the resultant ketal to purification by distillation to a specified chlorine content, hydrogenating the purified ketal in the presence of a hydrogenation catalyst preadjusted to an alkaline state, and reacting the resultant product with hydrochloric acid.

CONSTITUTION: A levulinic ester of formula 4 (wherein R is CH3, C2H5, C3H7, or C4H9) is ketalized with ethylene glycol by a known method. The resultant compd. of formula 1 is purified by distillation to a chlorine content of 10 ppm or lower and then is hydrogenated in the presence of a commonly used hydrogenation catalyst pretreated with an alcoholic alkali metal and/or alkaline earth metal hydroxide soln. to give 3-(2-methyl-1,3-dioxolan-2-yl)propan-1-ol of formula 2, which is reacted with hydrochloric acid. Thus is obtd. the objective compd. of formula 3 useful as a medicine precursor substance, etc., at a relative low technical cost without using a high-cost reagent.