α-Truxilic Acid of 4-Hydroxycinnamic Acid is a cyclobutane-based dicarboxylic acid formed through the photodimerization of 4-hydroxycinnamic acid (p-coumaric acid). It belongs to the truxilic acid family, characterized by rigid cyclic structures that influence their chemical and physical properties. This compound is significant in organic synthesis, pharmaceutical research, and materials science due to its structural stability and potential biological activity.