Occurs in dill oil, Anethum graveolus L., Umbelliferae. Isoln: G. Ciamician, P. Silber, Ber. 29, 1799 (1896); D. B. Spoelstra, Rec. Trav. Chim. 48, 372 (1929). Structure: H. Thoms, Arch. Pharm. 242, 344 (1904). Synthesis: W. Baker et al., J. Chem. Soc. 1934, 1681; F. Dallacker, Ber. 102, 2663 (1969); J. R. Cannon et al., J. Sci. Soc. Thailand 6, 59 (1980). Synergistic activity with insecticides: E. P. Lichtenstein et al., J. Agric. Food Chem. 22, 658 (1974); S.S. Tomar et al., Agric. Biol. Chem. 43, 1479 (1979).