Lilial

Synthesis

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

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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.

:[[File:2-(4-tert-Butylbenzyl)propionaldehyd Formulae V.1.svg|thumb|left|(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".

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.

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, 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.

References

References

1. (2010). "Real-Time Monitoring of Fragrance Release from Cotton Towels by Low Thermal Mass Gas Chromatography Using a Longitudinally Modulating Cryogenic System for Headspace Sampling and Injection". Analytical Chemistry.
2. "Lilial".
3. (1997). "Stereoisomeric flavour compounds LXXVI: direct enantioseparation, structure elucidation and structure-function relationship of 4-tert-butyl-α-methyldihydrocinnamaldehyde". Zeitschrift für Lebensmittel-Untersuchung und -Forschung A.
4. "COMMISSION REGULATION (EU) 2021/1902 OF 29 October 2021 amending Annexes II, III and V to Regulation (EC) No 1223/2009 of the European Parliament and of the Council as regards the use of cosmetic products of certain substances classified as carcinogenic, mutagenic or toxic for reproduction".
5. "Купить духи Salvador Dali Laguna — цена туалетной воды, фото, отзывы, описание аромата".