2,4-Dihydroxy-2,5-dimethyl-3(2H)-furan-3-one (Acetylformoin) was obtained from furanone via two steps. 2,4-Dihydroxy-2,5-dimethyl-3(2H)-furan-3-one diacetate (Ⅰ) was synthesized by acetoxylation, and then deacetylated by Novozym435 lipase to synthesize 2,4-Dihydroxy-2,5-dimethyl-3(2H)-furan-3-one (Ⅱ). The target compound was confirmed by 1H NMR, 13C NMR and HRMS. The thermal pyrolysis behavior of 2,4-Dihydroxy-2,5-dimethyl-3(2H)-furan-3-one was also investigated using online pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). The results indicated that the compound (Ⅱ) synthesized was the target product, and under these optimal conditions, the yield of 2,4-Dihydroxy-2,5-dimethyl-3(2H)-furan-3-one was above 70%. 2,4-Dihydroxy-2,5-dimethyl-3(2H)-furan-3-one after pyrolysis could migrates directly into cigarettes, and could also release release aroma substances with scorching sweet aroma, such as DDMP, furanone, maltol and other aromatic components. Adding 0.002% of the target product to cigarettes can significantly improve the flavor. The synthesized product had the functions of enhancing the caramel aroma quality of cigarette smoke and improving aftertaste. There is no significant difference in the hazard index of mainstream cigarette smoke between the cigarettes added with 2,4-Dihydroxy-2,5-dimethyl-3(2H)-furan-3-one and control, which indicates 2,4-Dihydroxy-2,5-dimethyl-3(2H)-furan-3-one is safe in cigarettes.