trans-2-Decenal

In short

trans-2-Decenal is an unsaturated fatty aldehyde found in coriander leaf and some citrus peels. It gives a waxy, orange-peel and cilantro-like note and is used at very low levels.

What trans-2-Decenal smells like

trans-2-Decenal is a powerful, fatty-waxy aldehyde that pairs orange with fresh coriander leaf. Neat, a supplier describes a fatty-waxy aldehydic note recalling rendered chicken fat; at perfumery levels orange zest appears alongside fresh coriander leaf. Bedoukian describes a fatty, diffusive orange odour with floral, rosy top notes, and a flavour panel at 1% found waxy, fatty, earthy, coriander, green and mushroom. Its taste is waxy citrus peel, especially orange and grapefruit.

Leading note: Waxy orange and coriander leaf
Clear facets: Fatty
Supporting facets: Rosy
Faint facets: Earthy, mushroom
Character: Fatty, waxy, diffusive, powerful

What makes trans-2-Decenal distinctive

The coriander leaf. Among the orange aldehydes it is the one with the green, soapy herb note of fresh coriander, and the fattiest neat.

Concentration and dilution

Fatty and waxy, with a rendered-fat note, neat; in dilution orange zest and fresh coriander leaf come forward. Powerful and diffusive even diluted.

How trans-2-Decenal is used

Used in traces for orange and coriander-leaf effects in citrus and green compositions, and in citrus flavours.

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

How trans-2-Decenal differs from similar materials

Aldehyde C-10 (Decanal): Decanal is the cleaner orange peel; trans-2-decenal adds fresh coriander leaf and is fattier neat.
cis-4-Decenal: cis-4-Decenal is juicier, cleaner mandarin; trans-2-decenal is fattier, with a coriander-leaf greenness.
trans-2-Dodecenal: trans-2-Dodecenal is the stronger cilantro-and-mandarin aldehyde, soapier and more tenacious; trans-2-decenal is fattier and more orange.

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

Potent: overdosing quickly makes a blend smell soapy or fatty. Store cold and protected from air.

Identity and classification

Type: Aroma chemical
Origin: Occurs in nature
Odour family: Aldehydic / Citrus
Note position: Top note
Physical form at room temperature: Liquid
Also known as: (E)-Dec-2-enal
CAS number: 3913-81-3
Molecular formula: C10H18O
Molecular weight: 154.25 g/mol
IUPAC name: (E)-dec-2-enal

The CAS number, formula and molecular weight are taken from PubChem compound 5283345, 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 (1,491 reports): H315 causes skin irritation (97.4% of reports). 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

Aldehyde C-10 (Decanal)
Aroma chemical · Aldehydic / Citrus — aldehydic, waxy, orange peel, fatty
Sweet Orange Oil
Essential oil · Citrus / Fruity — citrus, sweet, juicy, orange peel
Mandarin Oil
Essential oil · Citrus / Fruity — citrus, sweet, juicy, tangerine
Coriander Seed Oil
Essential oil · Spicy / Floral — spicy, floral, fresh, woody

Used in formulas and accords

Used in 1 published formula

trans-2-Decenal is an ingredient in 1 perfume formula in the Formula & Accord Library.

RUŌOD House Originals

Original compositions by RUŌOD House.

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

Questions about trans-2-Decenal

Is trans-2-Decenal natural or synthetic?

The molecule occurs in nature. Commercial trans-2-Decenal may be made by synthesis or obtained from natural sources, so check the supplier's specification if the distinction matters to you.

What is the CAS number of trans-2-Decenal?

3913-81-3. It was checked against PubChem on 19 October 2026.

Which published formulas use trans-2-Decenal?

trans-2-Decenal is used in 1 published formula in the RUŌOD Lab Formula & Accord Library: Lime Bruise. Each is listed with a link under "Used in formulas and accords" on this page.

Sources

PubChem — compound 5283345, checked 19 October 2026.
PubChem — GHS classification (the ECHA C&L Inventory notifications and any harmonised EU entry), read 26 October 2026.
The Good Scents Company — (E)-2-decenal (with Bedoukian's description and Mosciano's evaluation) — odour database.
Fraterworks — trans-2-decenal — distributor's description.
Wikipedia — 2-Decenal — published perfumery reference.
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.