Definition
ChEBI: A methyl ketone that is alpha-ionone in which a hydrogen at position 5 of the cyclohex-2-en-1-yl ring is substituted by a methyl group.
Description
α-Irone has a characteristic orris and violet-like odor. The commercially prepared product corresponds generally to the α-isomer.
Chemical Properties
Yellowish liquid; Soluble in alcohol. A mixture of three isomers (α-, βand γ-irone).
Chemical Properties
α- Irone has a rich, floral and natural character and constitutes an important element in orris and violet compositions as
well as being useful when an exotic nuance is required. α-Irone is extremely diffusive, and it gives volume and tenacity to compositions. In combination with α-irisone (1:20, respectively) gives a natural orris effect.
Occurrence
Reported found in orris root, raspberry and flowers of Pittosporum sp
Preparation
By intramolecular thermal H-ene reaction of an allysilane.
Taste threshold values
Taste characteristics at 10 ppm: woody, fruity, raspberry, orris, and berry with seedy nuances.
General Description
Irone is a bioactive compound that is produced by an endophytic fungus in the rhizomes of Iris germanica.
Synthesis
Alpha-n-Methy lionone is synthesized by condensation of Methylethyl ketone with Citral, and cyclization of the resulting Pseudomethylionone. Cyclization may be carried out with Boron trifluoride or other agent.
Purification Methods
If large amounts are available, then fractionate through a Podbielniak column (p 10) or an efficient spinning band column, but small amounts are distilled using a Kügelrohr apparatus. The 4-phenylsemicarbazone has m 174-175o (165-165.5o). [IR: Seidel & Ruzicka Helv Chim Acta 35 1826 1952, Naves Helv Chim Acta 31 1280 1948, Lecomte & Naves J Chim Phys 53 462 1956, Beilstein 7 IV 378.]
