New Insights into the Reactivity of Biomass with Butenes for the Synthesis of Butyl Levulinates

This article reports a detailed study on the reactivity of levulinic acid and cellulose with 1‐butene and iso ‐butene for the catalytic formation of sec ‐ and tert ‐butyl levulinates. The influence of catalyst type and various solvent conditions have been investigated to assess the potential of a sustainable transformation. A very simple and efficient procedure was discovered by using reusable Amberlyst‐15 in the absence of solvent to form, from levulinic acid and iso ‐butene, tert ‐butyl levulinate (70 % yield), a compound very difficult to prepare by other means. sec ‐Butyl levulinate (66 % yield) was obtained by using Amberlyst‐15 in γ‐butyrolactone as a biosourced solvent. The original procedure was also extended notably by directly using cellulose as a reactant. In the presence of a catalytic amount of H 2 SO 4 , it was possible to form sec ‐butyl levulinate (19 % yield) from 1‐butene in a more efficient way than by using the alcohol as an esterifying agent.