The acid hydrolysis of some polyhalotropones and some reactions of the products were investigated. The treatment of 2, 5-dichlorotropone with hydrochloric or sulfuric acid afforded 2chloro-5-hydroxytropone (I) and a small amount of 5-chlorotropolone. The compound I gives only-one kind of the methyl ether and one kind of the acetyl or benzoyl derivative. From the methyl ether, 5-amino-and 5-methylamino-2-chlorotropone were derived. The methoxyl and the amino groups of these compounds are reactive to alkaline hydrolysis, giving I without any of the skeletal rearrangement usually observed in the alkaline treatment of similar 2-halotropones. The hydrolysis of 2, 4, 7-tribromotropone with hydrochloric acid gave 3, 6-dichlorotropolone and 7-chloro-4-hydroxytropolone. unsaturated ketone.