Lilial

Lilial (a trade name for lily aldehyde, also known as lysmeral or lilestralis) is a chemical compound commonly used as a perfume in cosmetic preparations and laundry powders, often under the name butylphenyl methylpropional. It is an aromatic aldehyde, naturally occurring in crow-dipper and tomato plants,^[2] and produced synthetically in large scale. It was banned for use in cosmetics by the EU in March 2022 after being found to be harmful to fertility.

Lilial

Names
IUPAC name 3-(4-tert-Butylphenyl)-2-methylpropanal
Other names 4-tert-Butyl-α-methyl-benzenepropanal 4-tert-Butyl-α-methyl-hydrocinnamaldehyde Butylphenyl methylpropional
Identifiers
CAS Number	80-54-6 (Racemic) Y 75166-31-3 (2R) Y 75166-30-2 (2S) Y
3D model (JSmol)	Interactive image
ChemSpider	1266494 (2R) 1363748 (2S) 199342
ECHA InfoCard	100.001.173
EC Number	201-289-8
PubChem CID	1549660 (2R) 1715213 (2S) 228987
RTECS number	MW4895000
UNII	T7540GJV69 (Racemic) Y 14X71K3AMT (2R) Y WP1PPC4R9G (2S) Y
UN number	3082
CompTox Dashboard (EPA)	DTXSID9026500
InChI InChI=1S/C14H20O/c1-11(10-15)9-12-5-7-13(8-6-12)14(2,3)4/h5-8,10-11H,9H2,1-4H3 Key: SDQFDHOLCGWZPU-UHFFFAOYSA-N
SMILES CC(CC1=CC=C(C=C1)C(C)(C)C)C=O
Properties
Chemical formula	C14H20O
Molar mass	204.313 g·mol−1
Appearance	Clear viscous liquid
Density	0.94 g/cm3
Melting point	−20 °C (−4 °F; 253 K)
Boiling point	275 °C (527 °F; 548 K)[1]
Solubility in water	0.045 g/L at 20 °C
log P	4.36 [1]
Pharmacology
Routes of administration	Topical
Related compounds
Related aldehydes	Bourgeonal Isobutyraldehyde Hexyl cinnamaldehyde 2-Methylundecanal
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

It is also used as an intermediate in the synthesis of agrochemicals such as fenpropimorph and fenpropidin.

Synthesis

Lilial is produced by the mixed aldol coupling of 4-tert-butylbenzaldehyde (typically as it's methanol acetal) and propionaldehyde, followed by hydrogenation.

Properties

Lilial is commonly produced and sold as a racemic mixture; however, testing has indicated that the different enantiomers of the compound do not contribute equally to its odor. The (R)-enantiomer has a strong floral odor, reminiscent of cyclamen or lily of the valley; whereas the (S)-enantiomer possesses no strong odor.^[3]

(R)-Lilial (top) and (S)-lilial

Like most aldehydes, lilial is not long term stable and tends to slowly oxidize on storage.

Safety

The Scientific Committee on Consumer Safety (SCCS, scientific committee for consumer safety of the EU Commission) concluded in May 2019 that the use of lilial in both rinse-off and leave-on cosmetics "cannot be considered as safe".^[4]

After animal studies found it to be toxic for reproduction, it was reclassified as a prohibited substance in the EU, and banned from use in cosmetics as of March 2022.^[5]

It can sometimes act as an allergen and may cause contact dermatitis in susceptible individuals. Lilial was used in many perfumes (examples: Byredo Inflorescence, Salvador Dali Laguna,^[6] Elizabeth Arden 5th Avenue, etc.) produced before 2022 as a synthetic substitute for the scent of lily of the valley. Due to the ban on the use of lilial, safe analogues are currently used in perfume production.

See also

• Helional
• Bourgeonal