A Greener Olefination Process to Produce Alkenoic Acids from Levulinic Acid

Levulinic acid (LA) is a bifunctional compound with high reactivity that can be produced by acid hydrolysis of biomass. Its ketone group can be functionalized to an olefinic bond via Wittig reaction. However, this reactional system usually involves multiple steps and uses highly toxic raw materials. This study aims to produce alkenoic acids derived from LA via Wittig reaction using a greener process. For this, we evaluated the olefination of LA in the presence of different bases (NaHCO3, Na2CO3, and NaOH) and isopropanol as solvent (reduced toxicity). The products were identified by mass spectrometry, observing positive results for NaHCO3. The fragmentation mechanisms for the alkenoic acid ions (4-methyl-hex-4-enoic acid, m/z 127, and 4-methyl-hept-4-enoic acid, m/z 141) confirmed their production by the proposed process.