A constituent of Spanish verbena oil (from Verbena triphylla L., Verbenaceae): Kerschbaum, Ber. 33, 885 (1900). Prepn from α-pinene: Bain, Gary, US 2911442 (1959 to Glidden). Structure: Blumann, Zeitschel, Ber. 46, 1178 (1913); Weinhaus, Schumm, Ann. 439, 20 (1924). Absolute configuration: Hurst, Whitham, J. Chem. Soc. 1960, 2864. Review: J. L. Simonsen, The Terpenes vol. II (University Press, Cambridge, 2nd ed., 1949) p 232-239.