5-Methyl-2-(1-methylethenyl)-4-hexenoic Acid is a proposed intermediate in the synthesis of 1,1,5,5-Tetramethyl-2-(1-methylethenyl)cyclohexane (T305630), which is analyzed in synthetic elastomers and natural rubber studies of cyclic oligomer formation in the copolymerization of isoprene with isobutylene.