α-Chlorocycloalkanones(Ⅳ) were synthesized from cycloalkanones via potassiumα-oxocycloalkylsulfonates(Ⅱ).A two-step mechanism was proposed to explain the formation ofⅣfromⅡ. α-Chlorocycloalkanones (Ⅳ) were synthesized from cycloalkanones via potassium α-oxocycloalkyl sulfonates (Ⅱ). A two-step mechanism was proposed to explain the formation of Ⅳ from Ⅱ.