Occurs in parsley oil, Petroselinum sativum: Blanchet, Sell, Ann. 6, 259 (1833); Vongerichten, Ber. 9, 1477 (1876); Kolesnikov et al., Aptechnoe Delo 7(4), 27 (1958), C.A. 54, 12491e (1960). Structure: Ciamician, Silber, Ber. 23, 2283 (1890); Thoms, ibid. 36, 1714 (1903). Synthesis: Baker, Savage, J. Chem. Soc. 1938, 1602; F. Dallacker, Ber. 102, 2663 (1969). Synergistic activity with insecticides: E. P. Lichtenstein et al., J. Agric. Food Chem. 22, 658 (1974).