trans-2-Dodecenal

What trans-2-Dodecenal smells like

trans-2-Dodecenal is the smell of fresh cilantro, with a waxy mandarin-peel side. Suppliers describe a powerful aldehydic, mandarin, citrus-like odour, and Sigma-Aldrich, which also lists it as mandarin aldehyde, gives fatty, orange and citrus. It is one of the volatile components of coriander leaf and coriander oil, and is credited with the herb's pleasant citrus character. A keyword list adds metallic, but no fuller description supports it. It is notably tenacious for an aldehyde of its kind.

Leading note

Fresh cilantro

Clear facets

Mandarin peel

Supporting facets

Waxy

Faint facets

Metallic

Character

Green, soapy, waxy, tenacious

• coriander leaf
• waxy
• mandarin
• metallic

What makes trans-2-Dodecenal distinctive

It is the cilantro note itself — green, soapy and citrusy at once — with a mandarin-peel waxiness that the orange aldehydes do not have.

How trans-2-Dodecenal is used

Used in traces for coriander-leaf and mandarin effects in citrus, green and spicy compositions, and in citrus and savoury flavours.

Typical role: modifier (used in small amounts to change the character of a blend).

How trans-2-Dodecenal differs from similar materials

trans-2-Decenal

trans-2-Decenal is fattier and more orange, with coriander as a secondary note; trans-2-dodecenal is cilantro first, soapier and longer-lasting.

Tridecene-2-nitrile

Tridecene-2-nitrile is a harsh, fatty mandarin with a sea-breeze nuance on dilution; trans-2-dodecenal is green cilantro with mandarin peel.

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

Work from a 0.1% or 1% dilution; at higher levels the soapy coriander note dominates.

Identity and classification

Type

Aroma chemical

Origin

Occurs in nature

Odour family

Aldehydic / Green

Note position

Top to heart note

Physical form at room temperature

Liquid

Also known as

(E)-Dodec-2-enal

CAS number

20407-84-5

Molecular formula

C12H22O

Molecular weight

182.3 g/mol

IUPAC name

(E)-dodec-2-enal

The CAS number, formula and molecular weight are taken from PubChem compound 5283361, whose own record lists this CAS number; checked 19 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 (1,644 reports): H315 causes skin irritation (100% of reports); H400 very toxic to aquatic life (84.9% of reports); H317 may cause an allergic skin reaction (81.2% of reports). A skin sensitiser classification concerns handling the neat material and the dose in a finished product; the IFRA Standards, where they apply, set the limits. 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

• Mandarin Oil

  Essential oil · Citrus / Fruity — citrus, sweet, juicy, tangerine

• Coriander Seed Oil

  Essential oil · Spicy / Floral — spicy, floral, fresh, woody

• Aldehyde C-12 Lauric (Dodecanal)

  Aroma chemical · Aldehydic / Floral — aldehydic, waxy, soapy, violet

• Lime Oil (Expressed)

  Essential oil · Citrus / Green — citrus, green, zesty, aromatic

Used in formulas and accords

Used in 2 published formulas

trans-2-Dodecenal is an ingredient in 2 perfume formulas in the Formula & Accord Library.

RUŌOD House Originals

Original compositions by RUŌOD House.

• Iron Rain

  RUŌOD House Creation · listed as “trans-2-Dodecenal 1% DPG”, at 1% in DPG

• Lime Bruise

  RUŌOD House Original · listed as “trans-2-Dodecenal 1% DPG”, at 1% in DPG

Further reading

• Aldehydes in Perfumery: The Aliphatic Aldehydes and How to Use Them

  What the aliphatic aldehydes smell like, what they do, how to dose them, which other aldehydes matter, and how to stop them oxidizing.

Questions about trans-2-Dodecenal

Sources

• PubChem — compound 5283361, checked 19 October 2026.
• PubChem — GHS classification (the ECHA C&L Inventory notifications and any harmonised EU entry), read 26 October 2026.
• Sigma-Aldrich — trans-2-dodecenal (mandarin aldehyde), organoleptic profile — manufacturer's description.
• ChemicalBook — trans-2-dodecenal (CAS 20407-84-5) — odour database.
• FooDB — (E)-2-dodecenal — odour database.
• Olfactory profile: the RUŌOD Lab team's synthesis of the published descriptions above, reviewed 20 October 2026. Evidence: more than one published description. Classification and the short description: revision 1. Descriptions of odour are judgement, not measurement.