iron(III) triflate, Fe(OTf)3, copper(II) triflate, Cu(OTf)2, and silver(I) triflate, AgOTf, show high catalytic activities. These reactions proceed through the carbon–carbonbondcleavage by a retro‐aldol reaction and were found to be highly regioselective even in the presence of other functional groups. This type of reaction can also be applied to the preparation of the keto esters during the synthesis