Isoln of (E,E)-form from natural coating of apples: Huelin, Murray, Nature 210, 1260 (1966); Murray, Aust. J. Chem. 22, 197 (1969); from Dufour's gland in ants: Cavill et al., Tetrahedron Lett. 1967, 2201. Isoln of (Z,E)-form from oil of perilla: T. Sakai, Y. Hirose, Bull. Chem. Soc. Jpn. 42, 3615 (1969). Oxidation products of farnesene are believed to cause scald, a serious storage disorder of apples. Four possible geometric isomers. Synthetic studies: Ruzicka, Helv. Chim. Acta 6, 490, 501 (1923); Ruzicka, Capato, ibid. 8, 267 (1925). Configuration of (E,E)-form confirmed by synthesis from trans-β-farnesene: Brieger et al., J. Org. Chem. 34, 3789 (1969). Stereospecific synthesis of (E,Z)- and (Z,Z)-isomers: Anet, Aust. J. Chem. 23, 2101 (1970). Synthesis of (E,E)-form: Tanaka et al., J. Am. Chem. Soc. 97, 3252 (1975). (E,E)- and (Z,E)-forms are components of aphid alarm pheromones: J. A. Pickett, D. C. Griffiths, J. Chem. Ecol. 6, 349 (1980); of the trail pheromone of red imported fire ants: R. K. Vandermeer et al., Tetrahedron Lett. 22, 1651 (1981).