Olfactory Chemistry: Hedione- My Fair Jasmine

2

When you look back at perfumery there are some specific moments where the use of a new aroma chemical sparks a flurry of creativity. In 1966 perfumer Edmond Roudnitska introduced the world to Hedione in the classic men’s perfume Christian Dior Eau Sauvage.

Hedione was a synthetic jasmine discovered by chemist Edouard Demole. Dr. Demole was part of the team at Firmenich who discovered that the component in natural jasmine essential oil was a molecule called Methyl Jasmonate. From a synthetic perspective the double bond was problematic as far as synthesizing and making large quantities of this molecule. Dr. Demole discovered if he removed the double bond he formed a transparent version of jasmine chemically called Methyl Dihydrojasmonate and trademarked as Hedione.

hedione1

For many jasmine essential oil was a very difficult ingredient to use in moderation. Not only for the strong floral character but also for the presence of strong-smelling indoles in high percentage it made jasmine something which was strong. Maybe too strong. Hedione was a version of jasmine in which Dr. Demole played Henry Higgins and cleaned up jasmine removing the filthy skanky indoles. He also made it much less overwhelming. Hedione provides a unique middle ground between volatile top note and heavier base note. It is probably overstating things a bit to call Hedione the missing link for many perfumers looking for a diffusive floral transparency but it has been a part of thousands of perfumes over the last fifty years.

You will notice that unlike the drawing of Methyl Jasmonate which has the dashed and solid wedges to designate a specific geometry I didn’t draw Hedione that way because it is a mixture of all four possible variations. The chemists at Firmenich would go on to continue to synthesize ever more specific structures of that mixture. It would take thirty-seven years, in 1993, when it was discovered if you had a mixture of the two compounds shown below you got an enriched effect by having the two compounds where the side chains were on the same side of the molecule. This is called cis- in chemistry speak. In the structure of Methyl Jasmonate above that would be called trans- when the side chains are on different sides.

hedionehcparadisone

The mixture would be called Hedione HC which stood for “High Cis” meaning a high percentage of the cis-isomers. It would take three more years to develop a synthesis of the single isomer responsible for most of the effect in Hedione, and Hedione HC. That is the structure on the right and it is called Paradisone.  Paradisone is Hedione on steroids as now there is nothing to attenuate the power. The shy Eliza Doolittle of Hedione has become a stunning version which turns heads.

Perfumer Alberto Morillas has been one of the more contemporary perfumers who uses these molecules in interesting ways. One of the more recent uses of both Hedione and Paradisone was in 2013’s Penhaligon’s Iris Prima. Together they make the jasmine and iris heart feel like it has no horizon, almost infinitely expansive.

It may have taken forty years for the chemists at Firmenich to finally arrive at Paradisone but it all started with a simple reduction of a double bond on the natural molecule.

Mark Behnke

2 thoughts on “Olfactory Chemistry: Hedione- My Fair Jasmine

Leave a Reply

Your email address will not be published. Required fields are marked *

*