α-Isomethylionone has a fine violet and orris-like odor. This substance may be synthesized by condensation of citral with methyl
ethyl ketone controlling the ratio between the n- and iso-forms;
the methyl pseudo-ionone obtained is then subjected to ring closure, using strong alkali and high temperature (thus favoring the
formation of the normal α- and β-methylionones) or with quaternary ammonium base (thus favoring the formation of wo-forms);
See also monographs of α- and β-ionone and methyl α-, β-, and
γ-ionones.
α-Isomethylionone has a fine violet and orris-like odor.
By condensation of citral with methyl ethyl ketone controlling the ratio between the n- and iso-forms; the methyl pseudoionone obtained is then subjected to ring closure, using strong alkali and high temperature (thus favoring the formation of iso-forms);
See also monographs of α-, β-, and γ-ionones.
ChEBI: 3-Methyl-4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-3-buten-2-one is a sesquiterpenoid.
Flammability and Explosibility
Not classified
As a fragrance allergen, a-isomethylionone has to be
mentioned by name in cosmetics within the EU.
