The jasmine that was missing from jasmine
In the late 1950s a chemist at Firmenich, Edouard Demole, was taking jasmine absolute apart to find out what made it smell the way it did. The absolute is a dense, expensive extract, and most of what is in it had already been named. Demole found a minor component, present in tiny amounts, that did not smell like much on its own and yet seemed to carry the fresh, radiant quality of the living flower that the heavier materials lacked. He published its structure in 1962 as methyl jasmonate.
Making methyl jasmonate itself was awkward. Making a slightly simpler relative, with one double bond fewer, was not, and that relative turned out to be the more useful material. Firmenich named it Hedione, from the Greek for pleasure, and in 1966 Edmond Roudnitska put it into Eau Sauvage for Dior. The perfume is still sold, and its opening still reads as the moment the material arrived.
What it smells like
Almost nothing, at first. Hedione is a clear liquid with a faint, watery, citrusy-floral air about it, and a beginner who smells it on a strip wonders what the fuss is. Its effect is not its own smell but what it does to everything around it: it adds lift and space, makes florals smell like flowers on the stem rather than in a vase, and gives a formula the sense that the air is moving through it. Perfumers talk about it as a transparency material, and it is dosed in amounts that would be absurd for almost anything else, often a tenth of the whole concentrate or more.
The isomers
The ordinary material is a mixture. Of its four possible isomers, one, the cis form, is far more powerful and far more floral than the others, and several houses sell enriched versions under names like Hedione HC and Paradisone. They smell like the ordinary material with the volume turned up, and they let a perfumer get the same effect at a fraction of the dose. The catalog lists them separately because, at the bench, they behave like different materials.
Why it matters to the craft
A great deal of modern perfumery is built on materials that do not smell like much by themselves, and Hedione is the first and clearest example. It changed what a perfume could be allowed to smell like: lighter, airier, less of a thing and more of a weather. Most fresh masculine perfumes since Eau Sauvage, and most sheer florals since the 1990s, have it in them, and many have a great deal of it.
Open Hedione on your bench Its catalog page What replaces it
Sources: firmenich.com · Demole, E., Lederer, E., Mercier, D. (1962). Helvetica Chimica Acta 45, 675. Isolation and structure of methyl jasmonate.