Bio-based Pentenoic Acids as Intermediates to Higher Value-Added Mono- and Dicarboxylic Acids

The acid catalyzed reactive distillation of gamma-valerolactone yields pentenoic acids (PEAs) which can be obtained in > 90% purity and > 97% selectivity. The PEAs (five isomers) can be converted into a number of useful products with commercial relevance. The hydroxycarbonylation of PEAs yields adipic acid (a Nylon monomer) in very high selectivity and with good activity. Self-metathesis of PEAs yields C6 - C8 unsaturated dicarboxylic acids which after hydrogenation produces a mixture of adipic acid, pimelic acid and suberic acid. If the PEAs are first subjected to ethenolysis; acrylic acid, 3-butenoic acid, and 4-pentenoic acid are produced. The self-metathesis of 3-butenoic acid produces beta-hydromuconic acid in > 99% selectivity which can be hydrogenated to adipic acid, whereas the self-metathesis of 4-PEA followed by hydrogenation gives suberic acid with 99% selectivity. 3-Butenoic acid can also be hydroxycarbonylated to produce glutaric acid in 99% selectivity.