Synthetic musk

Synthetic musks, known as white musks in the perfume industry, are a class of synthetic aromachemicals to emulate the scent of deer musk or other natural musk. Synthetic musks have a clean, smooth and sweet scent lacking the fecal/"animalic" notes of natural musks and are sometimes attributed as having notes of blackberry, ambrette or ambergris. These compounds are essential in modern perfumery and form the base note foundations of most perfume formulas. Most, if not all musk fragrance used in perfumery today is synthetic.

Synthetic musks can be divided into three major classes — aromatic nitro musks, polycyclic musk compounds, and macrocyclic musk compounds. The first two groups have broad uses in industry ranging from cosmetics to detergents.

An artificial musk was obtained by Albert Baur in 1888 by condensing toluene with isobutyl bromide in the presence of aluminium chloride, and nitrating the product. It was discovered accidentally as a result of Baur's attempts at producing a more effective form of trinitrotoluene (TNT). It appears that the odour depends upon the symmetry of the three nitro groups.

Polycyclic musks are defined by the International Fragrance Association (IFRA) as fragrance ingredients with the following olfactive and structural features:

Polycylic musks that fit this definition are:

The creation of this class of musks was largely prompted through the need for eliminating the nitro functional group from nitro-musks due to their photochemical reactivity and their instability in alkaline media. This was shown to be possible through the discovery of ambral, a non-nitro aromatic musk, which promoted research in the development of nitro-free musks. This led to the eventual discovery of phantolide, so named due to its commercialization by Givaudan without initial knowledge of its chemical structure (elucidated 4 years later). While poorer in smell strength, the performance and stability of this compound class in harsh detergents led to its common use, which spurred further development of other polycyclic musks including Galaxolide.

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