Linalyl acetate

Description

Linalyl acetate belongs to monoterpene compound. It is a naturally occurring phytochemical found in many flowers and spice plants. It is the one of the principle components of essential oils of bergamont and lavender.¹ It is a clear, colorless liquid with a boiling point of 220°C. Chemically, it is the acetate ester of linalool, and the two often occur in conjunction in the essential oils of Lavender and Lavandin.²
Linalyl acetate is an approved flavoring food additive. It is the most important fragrance ingredient for bergamot, lilac, lavender, linden, neroli, ylang-ylang, and fantasy nots. It is used in decorative cosmetics, fine fragrances, shampoos, toilet soaps and other toiletries as well as in non-cosmetic products such as household cleaners and detergents.^3,4

Reference

1. https://pubchem.ncbi.nlm.nih.gov/compound/linalyl_acetate#section=Top
2. A. Martin, V. Silva, L. Perez, J. Garcia-Serna, M. J. Cocero, Direct Synthesis of Linalyl Acetate from Linalool in Supercritical Carbon Dioxide: A Thermodynamic Study, Chemical Engineering & Technology, 2007, vol. 30, pp. 726-731
3. H. Surbung, J. Panten, Common Fragrance and Flavor Materials: Preparation, Properties und Uses, 2006, ISBN 978-3-527-31315-0
4. C. S. Letizia, J. Cocchiara, J. Lalko, A. M. Api, Fragrance material review on linalyl acetate, Food and Chemical Toxicology, 2003, vol. 41, pp. 965-976

Chemical Properties

Linalyl Acetate occurs as its isomer as the main component of lavender oil (30–60%, depending on the origin of the oil), of lavandin oil (25–50%, depending on the species), and of bergamot oil (30–45%). It has also been found in clary sage oil (up to 75%) and in a small amount in many other essential oils. Racemic linalyl acetate is a colorless liquid with a distinct bergamot–lavender odor.

Linalyl acetate is used extensively in perfumery. It is an excellent fragrance material for, among others, bergamot, lilac, lavender, linden, neroli, ylang-ylang, and fantasy notes (particularly chypre). Smaller amounts are used in other citrus products. Since linalyl acetate is fairly stable toward alkali, it can also be employed in soaps and detergents.

Chemical Properties

Linalyl acetate has a characteristic bergamot–lavender odor and persistent sweet, acrid taste.

Occurrence

Reported found in the essential oils of bergamot, lavender, clary sage and lavandin; also identified among the constituents of the essential oils of Salvia officinalis, petitgrain, sassafras, neroli, lemon, Italian lime, jasmine, Mentha citrata, Mentha aquatica, Thymus mastichina, etc; also reported in abundant quantities in the essential oil from flowers, leaves and stems of Tagetes patula, in the distillate from leaves of Citrus aurantifolia from India, and in the essential oil of Mentha arvensis. Also reported found in citrus peel oils and juices, berries, peach, celery, tomato, cinnamon, clove, nutmeg, pepper, thymus, grape wines, avocado, mushroom, marjoram, mango, cardamom, coriander, gin, origanum, lovage, laurel, myrtle leaf, rosemary, sage and mastic gum oil.

Uses

Linalyl Acetate ermentative production of medium or short chain length alcohol, esters and/or glucosides by metabolically engineered microorganism.

Uses

In perfumery.

Preparation

Linalyl acetate is synthesized by two methods:
1) Esterification of linalool requires special reaction conditions since it tends to undergo dehydration and cyclization as it is an unsaturated tertiary alcohol. These reactions can be avoided as follows: esterification with ketene in the presence of an acidic esterification catalyst below 30 °C results in the formation of linalyl acetate without any by-products. Esterification can be achieved in good yield, with boiling acetic anhydride, whereby the acetic acid is distilled off as it is formed; a large excess of acetic anhydride must be maintained by continuous addition of anhydride to the still vessel. Highly pure linalyl acetate can be obtained by transesterification of tert-butyl acetate with linalool in the presence of sodium methylate and by continuous removal of the tert-butanol formed in the process.
2) Dehydrolinalool, obtained by ethynylation of 6-methyl-5-hepten-2-one, can be converted into dehydrolinalyl acetatewith acetic anhydride in the presence of an acidic esterification catalyst. Partial hydrogenation of the triple bond to linalyl acetate can be carried out with, for example, palladium catalysts deactivated with lead.

Definition

ChEBI: 3,7-dimethylocta-1,6-dien-3-yl acetate is a monoterpenoid that is the acetate ester of linalool. It forms a principal component of the essential oils from bergamot and lavender. It is an acetate ester and a monoterpenoid. It is functionally related to a linalool.

Aroma threshold values

Detection: 1 ppm

Taste threshold values

Taste characteristics at 5 ppm: floral, green, waxy, terpy, citrus, herbal and spicy nuances.

General Description

Linalyl acetate is a monoterpene ester mainly found in lavandula essential oil. It is used as a flavoring agent in food industries, as well as a preservative additive in cosmetics and fragrances such as soaps, colognes, perfumes, and skin lotions.

Contact allergens

Structurally close to linalool, linalyl acetate is the main component of lavender oil and is commonly used in fragrances and toiletries, and in household cleaners and detergents as well. By autoxidation, it leads mainly to hydroperoxides, with a high sensitizing potent.

Synthesis

Normally prepared by direct acetylation of linalool; another method starts from myrcene hydrochloride, anhydrous sodium acetate and acetate anhydride in the presence of a catalyst; all synthetic methods tend to avoid the simultaneous formation (because of isomerization) of terpenyl and geranyl acetate.