Synthesis and Pyrolysis of Selected Metal Levulinates

Eight metal levulinate salts of Mg2+, Ca2+, Sr2+, Ba2+, La3+, Fe3+, Cu2+, and Zn2+ were prepared by reacting the corresponding hydroxides with equivalent amounts of levulinic acid in water. Pyrolysis of the salts at 350 A degrees C for 3.0 min produces colorless liquid pyrolysate oils in yields of 100-567 g kg(-1) dry salt. The pyrolysates were analyzed by H-1 NMR and GC-MS. The group II metal levulinates produced pyrolysate oils of similar composition with 3-methyl-2-cyclopentenone, 2,3-dimethyl-2-cyclopentenone, and gamma-valerolactone as the major compounds. The La3+ and Fe3+ levulinates produced pyrolysates with 3-methyl-2-cyclopentenone, 2,3-dimethyl-2-cyclopentenone, gamma-valerolactone, and levulinic acid as the major compounds. The Cu2+ and Zn2+ salts produced pyrolysates with levulinic acid as the major compound.