An unknown compound burned with a yellow, nonsmoky flame and was found to be insoluble in 5% sodium hydroxide solution but soluble in concentrated sulfuric acid. Measurement of its boiling point gave a range of 130–131°C. Combustion analysis gave a molecular formula of C5H8O. It was found to give a semicarbazone with a melting point of 204–206°C. However, it gave a negative result when treated with Tollens reagent, and it did not decolorize the Baeyer reagent. It also gave a negative iodoform test. Identify the unknown compound.