Hedione®

Other comments :

Stability :

Stable in perfumes and diverse functional bases
Hedione® HC is quite unstable and tends to convert into trans-Hedione®.

Uses in perfumery :

Hedione® is used in jasmine reconstitutions, and all kinds of accords, to give volume to the whole, to accompany and give tenacity to the perfume. Allows, in association with Bergamot EO, Beta-Ionone and Damascone-beta, to recreate a tea note for example. Present in a large majority of commercial fragrances.

Year of discovery :

Discovered in 1960, Hedione® was sold at that time for 7500 suiss francs per kilogram. This price really decreased. Patent N°CH382731A published on feb 25, 1960 by Demole.E et Lederer.E for Firmenich et Cie. ''Hedione® '' tradename has been published and protected by Firmenich SA since 04/09/1972 (brand N°392334)

Isomerism :

Hedione®, commonly used in perfumery, is actually a 9:1 mixture of trans:cis diastereoisomers of the molecule. However, cis-Hedione® is the most powerful isomer. Its detection threshold is seventy times lower than trans-Hedione®. Thus, some Hedione® enriched in cis isomer are marketed: Cepionate® (30% cis), Kharismal® (60% cis) and Hedione® HC (for ''high cis '') (75% cis). Nevertheless, this Hedione® tends to be more unstable than the classic Hedione®, as it isomerizes in its trans form, more stable. Hedione® HC is prepared by a specific distillation technique that involves sodium carbonate. Another method is to hydrogenate the corresponding cyclopenteneacetic acid by a ruthenium II catalysis, followed by a methanol esterification of the acid function.

Synthesis precursor :

The classic Hedione® is a mixture of isomers, it is used to isolate Hedione® HC (High Cis), a superior olfactory quality and power (also to be notes : Cepionate®, Kharismal® and Paradisone®)

Natural availability :

Hedione® is present in trace amounts in Grandiflorum Jasmine Absolute and in some teas. It is nevertheless exclusively synthetic Hedione® that is used in perfumery.

Synthesis route :

Hedione® is synthesized from a condensation between cyclopentanone and valeraldehyde, followed by an isomerization of the intermediate product obtained to give 2-pentyl-2-cyclopenten-1-one. This molecule can undergo a Michael addition by reacting it with an alkyl malonate. A hydrolysis followed by a decarboxylation and finally an esterification (using methanol and an acid catalysis) of the acid function that has formed, allows to synthesize the final product, Hedione®.