(E)-4-Methylpent-2-enoic acid is primarily utilized in organic synthesis as a building block for the production of various chemical compounds. It serves as an intermediate in the synthesis of pharmaceuticals, agrochemicals, and specialty chemicals. Its structure allows it to participate in reactions such as esterification, amidation, and polymerization, making it valuable in the development of polymers and resins. Additionally, it is used in the creation of flavor and fragrance ingredients due to its ability to contribute to specific aromatic profiles. In research, it is employed as a reagent in studies involving organic transformations and the development of new synthetic methodologies.