The reaction of fluoral hydrate with carbohydrazides in methanol in the presence of molecular sieves (4 Å) gave the desired N-acylated fluoral hydrazones (3a–f) in fair yields. Treatment of the latter with mercaptoacetic acid in benzene led to the corresponding 2-trifluoromethyl-1,3-thiazolidinone derivatives (4a–f), whereas the reaction with acetic anhydride gave 3-acetyl-2,3-dihydro-2-trifluoromethyl-1,3,4-oxadiazoles (5a–f). The structures of each type of product have been established by X-ray crystallography.