In short
Octahydrocoumarin, sold as bicyclononalactone, is a lactone used as a coumarin alternative with a tonka character. It is a mixture of diastereoisomers.
What Octahydrocoumarin smells like
IFF markets bicyclononalactone as very useful in preparing coumarin alternatives: more stable than coumarin, with a very good tonka character, almond, vanilla, hay and coconut notes, used up to 10%. A Parchem specification gives a sweet, creamy, lactonic odour with coconut and coumarin and milky vanilla nuances. JECFA records only a slight spicy note.
- Leading note
- Tonka
- Clear facets
- Coumarin
- Supporting facets
- Coconut
- Faint facets
- Almond, hay
- Character
- Creamy, sweet
What makes Octahydrocoumarin distinctive
Coumarin's tonka effect from a saturated lactone, more stable than coumarin itself.
Where the descriptions disagree: JECFA notes only a slight spicy note; suppliers describe a full coumarin-tonka-coconut profile, and ChemicalBook a sharp, fatty one.
How Octahydrocoumarin is used
IFF recommends it up to 10% when building coumarin alternatives and tonka effects.
Typical role: modifier (used in small amounts to change the character of a blend).
How Octahydrocoumarin differs from similar materials
- Dihydrocoumarin
- Dihydrocoumarin is coumarin softened with cream, tonka-hay with coconut and almond milk; octahydrocoumarin is the saturated lactone, a more stable tonka-coconut note.
Each difference compares the published descriptions of the two materials. Smell varies with grade, supplier and dilution; compare them side by side on blotters before substituting one for another.
Formulation considerations
A mixture of diastereoisomers. JECFA notes only a slight spicy note; the trade descriptions are fuller.
Identity and classification
- Type
- Aroma chemical
- Origin
- Synthetic
- Odour family
- Gourmand / Powdery
- Note position
- Heart to base note
- Physical form at room temperature
- Liquid
- Also known as
- Bicyclononalactone
- CAS number
- 4430-31-3
- Molecular formula
- C9H14O2
- Molecular weight
- 154.21 g/mol
- IUPAC name
- 3,4,4a,5,6,7,8,8a-octahydrochromen-2-one
The CAS number, formula and molecular weight are taken from PubChem compound 20487, whose own record lists this CAS number; checked 24 October 2026.
Safety and compliance
Hazard classification of the neat substance, as PubChem summarises it, read 26 October 2026. Companies notifying the ECHA C&L Inventory classify it (1,651 reports): H319 causes serious eye irritation (78% of reports). 243 of the reports find it does not meet the hazard criteria. Unless it is harmonised, this is the notifiers' own classification, not a binding one.
This page is general information, not a safety assessment or a specification. Confirm identity, composition, IFRA status and allergen content from your supplier's documents for the lot you hold.
Materials it works with
-
Coumarin
Aroma chemical · Powdery / Fougère — hay, sweet, almond, tobacco
-
Tonka Bean Absolute
Absolute · Gourmand / Powdery — coumarinic, hay, almond, sweet
-
Vanillin
Aroma chemical · Gourmand / Amber — vanilla, sweet, creamy
Used in formulas and accords
Used in 8 published formulas
Octahydrocoumarin is an ingredient in 5 perfume formulas and 3 accords in the Formula & Accord Library.
Community formulas
RUŌOD House Originals
Original compositions by RUŌOD House.
Further reading
Questions about Octahydrocoumarin
Is Octahydrocoumarin natural or synthetic?
Octahydrocoumarin is synthetic — it is made by chemical synthesis.
What is the CAS number of Octahydrocoumarin?
4430-31-3. It was checked against PubChem on 24 October 2026.
Which published formulas use Octahydrocoumarin?
Octahydrocoumarin is used in 8 published formulas in the RUŌOD Lab Formula & Accord Library, including Apricot Dust, Bracken Moon and Coconut Accord. Each is listed with a link under "Used in formulas and accords" on this page.
Sources
- PubChem — compound 20487, checked 24 October 2026.
- PubChem — GHS classification (the ECHA C&L Inventory notifications and any harmonised EU entry), read 26 October 2026.
- IFF — Bicyclononalactone — manufacturer's description.
- Parchem — octahydrocoumarin — distributor's description.
- PubChem — Octahydrocoumarin (CID 20487): JECFA organoleptic description — odour database.
- Olfactory profile: the RUŌOD Lab team's synthesis of the published descriptions above, reviewed 26 October 2026. Evidence: more than one published description. Classification and the short description: revision 1. Descriptions of odour are judgement, not measurement.