The fragrant principle of violets, best isolated from the rhizomes of iris or from orris oil: F. Tiemann, P. Kruger, Ber. 26, 2675 (1893); Ruzicka et al., Helv. Chim. Acta 16, 1143 (1933); Naves, Mazuyer, Les Parfums Naturels (Paris, 1939). Irone, as isolated, is an isomeric mixture of α-, β, and γ-irones, q.q.v., with each having the same molecular formula, C14H22O . Synthesis of isomeric mixture: Eschinazi, US 3019265 (1962 to Givaudan).