Title: Ionone
Trademarks: Irisone (Givaudan)
Molecular Formula: C13H20O
Molecular Weight: 192.30
Percent Composition: C 81.20%, H 10.48%, O 8.32%
Literature References: Mixture in which the major constituents are a-ionone, (E)-4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-3-buten-2-one, and b-ionone, (E)-4-(2,6,6-trimethyl-1-cyclohexen-1-yl)-3-buten-2-one. The latter is a key intermediate in the synthesis of vitamin A. Isoln from the volatile oil of Boronia megastigma Nees., Rutaceae: Naves, Parry, Helv. Chim. Acta 30, 419 (1946). Prepn by condensing citral with acetone: Tremann, Schmidt, Ber. 33, 3703 (1900); Hibbert, Cannon, J. Am. Chem. Soc. 46, 119 (1924); Krishna, Joshi, J. Org. Chem. 22, 224 (1957). Prepn from isobutylene and vinyl methyl ketone: Pasedach, Seefelder, DE 1000374 (1957 to BASF), C.A. 54, 1595g (1960). Prepn by cyclization of pseudoionone with H2SO4: Kimel et al., J. Org. Chem. 22, 1611 (1957); Kaiser, Kimel, US 2877271 (1959 to Hoffmann-La Roche). Review: Naves, J. Soc. Cosmet. Chem. 22, 439 (1971).
Properties: Liquid. Odor reminiscent of cedar wood; in very dilute alcoholic soln it resembles the odor of violets. d2525 0.933-0.937. nD20 1.503-1.508. bp12 126-128°. uv max: a-ionone 228.5 nm (e 14300); b-ionone 293.5 nm (e 8700). Miscible with abs alc. Soluble in 2 to 3 parts of 70% alcohol, ether, chloroform, benzene. Very slightly sol in water.
Boiling point: bp12 126-128°
Index of refraction: nD20 1.503-1.508
Absorption maximum: uv max: a-ionone 228.5 nm (e 14300); b-ionone 293.5 nm (e 8700)
Density: d2525 0.933-0.937
CAUTION: May cause allergic reactions, Shultheiss, Dermatol. Wochenschr. 135, 629 (1967).
Use: In perfumery. |