Hexafluoroacetone and α-keto acids react to give 5, 5-bis (trifluoromethyl) substituted 2 (5H)- furanones and/or 2, 2-bis (trifluoromethyl)-1, 3-dioxolan-4-ones depending upon the substituent pattern of the side chain of the acid. A fluoroanalogue of the natural product zymonic acid was obtained from ethyl 3, 3, 3-trifluoropyruvate and 2-oxosuccinic acid in one step.