Volatile chemical found fungi; constituent of lavender oil. Mediates interactions between plants, herbivores, and their natural enemies. Isoln from bituminous tar: J. Herzenberg, E. v. Winterfeld, Ber. 64, 1025 (1931); from the essential oil of Rosmarinus officinalis L: A. Koedam, M. J. M. Gijbels, Z. Naturforsch. 33C, 144 (1978). Prepn: Y. R. Naves, Helv. Chim. Acta 26, 1034 (1943); P. G. Gassman, G. D. Richmond, J. Org. Chem. 31, 2355 (1966). Oxidation potential and uv spectrum: R. A. Day, Jr. et al., J. Am. Chem. Soc. 72, 1379 (1950). Role as an alarm pheromone in carpenter ants: R. M. Duffield, M. S. Blum, Comp. Biochem. Physiol. 51B, 281 (1975); in herbivore and parasitoid response profiles: R. Ramachandran et al., J. Agric. Food Chem. 39, 2310 (1991). Colorimetric determn: D. H. E. Tattje, C. Scholtens, Pharm. Weekbl. 94, 137 (1959). GC determn in lavender oil: P. A. Stadler, Helv. Chim. Acta 43, 1601 (1960). Extraction from king oyster mushrooms: J.-L. Mau et al., J. Agric. Food Chem. 46, 4587 (1998).