Water → 2-Propanone, 1-(1-oxopropoxy)-

To a solution of hydroxyacetone (190 g, 2.56 mol) and pyridine (210 ml, 2.6 mol) in ethyl acetate (1 L), propionyl chloride (197 g, 2.1 mol) was added dropwise at 5° C. The reaction liquid was stirred at room temperature for one hour, and then poured into water (700 ml). After phase separation, the organic layer was washed twice with a 1−N aqueous hydrochloric acid (700 ml), twice with water (700 ml), and once with saturated brine (500 ml), and dried over magnesium sulfate. After the magnesium sulfate was filtered out, the solvent was distilled off under reduced pressure, to obtain propionyloxyacetone (177 g, 1.36 mol). The thus-obtained propionyloxyacetone was used in the next process, without further purification.