In this issue the chemical identities of molecules with a more or less floral-jasmine-like odour-character will be discussed. A qualitative odour-structure relationship will be derived from the structure of chemical compounds with a jasmine odour.
Methyl jasmonate isomers
Methyl jasmonate is a cyclopentanone-derivative with on the 2-place in the ring a (Z)-2-pentenyl group and on the 3-place a methylene-acetate group. Methyl jasmonate occurs up to 0.5% in jasmine absolute and is the most characteristic compound for the jasmine odour. Because the product is rather expensive, several cheaper derivatives or analogues are on the market.
Methyl dihydrojasmonate is a more economic substitute for methyl jasmonate. The compound also contains the cyclopentanone ringsystem with on the 2-place a saturated C-5 chain, and on the 3-place the methylene-acetate group.
cis-Jasmone occurs up to 3% in jasmine absolute and also has the odour character of jasmine. This chemical compound has a cyclopent-2-enone ring with on the 2-place a (Z)-2-pentenyl group, however without the methylene-acetate on the 3-place. Jasmone is also rather difficult to produce and, as a consequence, expensive. Again, several derivatives or substitutes of the substance are on the market.
Jasminlactone and analogues
Jasminlactone is a delta-lactone corresponding with jasmone. It is present in jasmine absolute and in a wide range of other essential oils. The product has a lactonic, coconut-like, fruity odour with characteristics of jasmone. Several analogues of jasminelactone are produced on a technical scale.
Dihydro- and isojasmone
The odours of these compounds are reminiscent of that of jasmone. Dihydrojasmone is jasmone with a saturated side-chain.
Alpha-pentyl- and alpha-hexylcinnamicaldehyde are well-known economic jasmine compounds. The compounds have a good odour-tenacity and they are extensively used in perfume compounds for all purposes, except in those for functional perfumery in strongly acidic or alkaline media.
Ethyl 2-pentyl- and 2-hexyl-acetoacetate are completely synthetic jasmine compounds. The odours of these products are somewhat reminiscent of methyl dihydrojasmonate and jasmone.
Alkyl hydropyrane acetates
The 3-alkyl-4-acetate-tetrahydropyran compounds are also synthetic products, obtained by the condensation of, for instance, octene with formaldehyde in acetic acid and anhydride. The olfactive quality of these compounds slightly resembles that of jasmonates.
The characteristic profile of compounds with jasmine odour seems to be determined by the presence of three different groups around a central carbon atom, e.g. a strong polar functional group, an alkyl side chain having 5 or 6 carbon atoms, and a less polar group that can vary in structure.
All the chemical compounds with jasmine odour are described with their identity and performance in the Perfumery Materials & Performance database.
Reprinted by Leffingwell & Associates, 2006, with Permission