(1S,5R)-(+)-cis-alpha-irone - iris, sweet irone odour, woody ionone, floral, fruity (Galfry, et.al, by GC sniffing); Inoue, et. al., indicates the odor is Green, light; weak; Brenna, et. al. describe it as Violet like, with woody, methylionone undertones Odor Threshold = 100 ppm (100,000 ppb) also known as (2R,6S)-(+)-cis-alpha-irone Ref: A. Galfry, P. Martin and M. Petrizilka, J. Essent. Oil Res., 5, 265-277 (1993); T. Inoue, H. Kiyota & T. Oritani, Synthesis of both enantiomers of cis-alpha-irone and cis-gamma-irone, principal constituents of iris oil, via resolution of (±)-2,2,4-trimethyl-3-cyclohexene-1-carboxylic acid, Tetrahedron: Assymetry, 11(18), 3807-3818 (2000); Brenna, Elisabetta; Fuganti, Claudio; Fronza, Giovanni; Malpezzi, Luciana; Righetti, Annalisa; Serra, Stefano., Enzyme-Mediated Preparation of (+)- and (-)-cis-alpha-Irone and (+)- and (-)-trans-alpha-Irone, Helv. Chim. Acta, 82(12), 2246-2259 (1999); Elisabetta Brenna, Claudio Fuganti and Stefano Serra, Enantioselective perception of chiral odorants, Tetrahedron: Asymmetry, 14, 1–42 (2003)

(1R,5S)-(-)-cis-alpha-irone - odourless (Galfry, et.al, by GC sniffing); In contrast, Inoue, et. al., indicate the (-)-cis-alpha-irone fragrance is superior to its enantiomer with Single-floral, ionone-like notes; Brenna, et. al. describe it as slightly stronger with a distinct ‘orris-butter’ character Odor Threshold = 10 ppm (10,000 ppb) also known as (2S,6R)-(-)-cis-alpha-irone Ref: A. Galfry, P. Martin and M. Petrizilka, J. Essent. Oil Res., 5, 265-277 (1993); T. Inoue, H. Kiyota & T. Oritani, Synthesis of both enantiomers of cis-alpha-irone and cis-gamma-irone, principal constituents of iris oil, via resolution of (±)-2,2,4-trimethyl-3-cyclohexene-1-carboxylic acid, Tetrahedron: Assymetry, 11(18), 3807-3818 (2000); Brenna, Elisabetta; Fuganti, Claudio; Fronza, Giovanni; Malpezzi, Luciana; Righetti, Annalisa; Serra, Stefano., Enzyme-Mediated Preparation of (+)- and (-)-cis-alpha-Irone and (+)- and (-)-trans-alpha-Irone, Helv. Chim. Acta, 82(12), 2246-2259 (1999); Elisabetta Brenna, Claudio Fuganti and Stefano Serra, Enantioselective perception of chiral odorants, Tetrahedron: Asymmetry, 14, 1–42 (2003)

(1S,5S)-(+)-trans-alpha-irone - floral, fresh & fruity, irone and ionone type, honey, sweet chamomille effect, violet odour is weak (Galfry, et.al, by GC sniffing); Brenna, et. al. describe it as the weakest of the alpha-isomers Odor Threshold = NA also known as (2S,6S)-(+)-trans-alpha-irone Ref: A. Galfry, P. Martin and M. Petrizilka, J. Essent. Oil Res., 5, 265-277 (1993); Brenna, Elisabetta; Fuganti, Claudio; Fronza, Giovanni; Malpezzi, Luciana; Righetti, Annalisa; Serra, Stefano., Enzyme-Mediated Preparation of (+)- and (-)-cis-alpha-Irone and (+)- and (-)-trans-alpha-Irone, Helv. Chim. Acta, 82(12), 2246-2259 (1999); Elisabetta Brenna, Claudio Fuganti and Stefano Serra, Enantioselective perception of chiral odorants, Tetrahedron: Asymmetry, 14, 1–42 (2003)

Ionones, Irones, Damascones & Structurally Related Odorants

Acyclics (Alcohols, Esters, Acids, Aldehydes)

Lactones

Sesquiterpenoid Related Odorants