It’s been almost two months since my previous post in Chemistry Flash series which featured nerol and geraniol. I don’t really have any good explanation why I “abandoned” the series. Are exams a good explanation? Anyway I apologize for such a long break. Please forgive your friend!
In this episode I would like to tell you more and maybe teach you something interesting about muscone, one of the most popular aroma chemical in present perfumery.
Muscone is a compound built of 16 carbon atoms, 30 hydrogen atoms and one atom of oxygen, so it’s formula is C16H30O. One mol of muscone weights 238,4 grams and its density is lower than of the water. It’s easily soluble in water and it’s miscible with alcohol. From the 3D structure approach muscone is a 15-membered ring featuring a ketone group (at C-1 position) and a methyl group at C-3.
In the past not only perfume industry but also medicine could use natural musk. It was obtained from the glandular secretion of deer musk and from plans possesing a similar aroma. How did that work with animal musk then? The method required killing or finding a dead deer. The next step was to cut off, remove the gland – musk pot located close to the anus of the animal. Musk pot originally contains a dense paste in red-brown color.
Drying allows water and other liquid substances to evaporate and after a while a paste transforms into a powdery, granulated material known as musk grain. From musk grain an alcohol tincture was being made. It was then carefuly diluted because only certain concentrations of tincture can give you a pleasant odor which can be used in perfumery. But this method has its finest times long gone and it can be only mentioned as a historical one.
Extensive and not much controlled hunting for deer musks resulted in almost complete prohibition of this material in 19th century. Economy and ethics were main purposes of such decision. There was no other choice but to invent and adapt synthetic musk for perfumery purposes. Chemists are super creative and they found a relatively easy way of muscone synthesis. Muscone is the main ingredient responsible for a characteristic smell of musk. Below is the synthesis path.
It goes from citronellal, common chemical of a reasonable price. The reaction of assymetric synthesis of muscone ends with ring-closing metathesis. The process is relatively easy but the reactions are bit complicated even for someone who studies chemistry.
Muscone molecule structure and also it existence were proved by a Croatian chemist Leopold Ružička. He began the investigations of odoriferous compounds in 1916. Proving the existence and determining the structure of muscone was one of his greatest discoveries. In 1939 he was awarded with Nobel Prize for Chemistry. Chemistry of today is grateful for hiw numberous achievements which make chemistry of 21st century much easier.
Ružička had a support of the oldest perfume manufacturer in the world Haarman&Reimer (currently known as Symrise after H&R merged with Dragoco.)
Musk along with muscone is one of those aroma chemicals that can be described by many opposite words. Its smell cany vary from very animalic, reminding of excrement, urine, grease, oily fur on the one side of the spectrum to the aroma of clean materials, freshly ironed sheets and new-born child skin on the other side of the spectrum.
Deer musk is not the only animal that can produce compounds of musk odour. Others like muskrat, musk duck, muskox (musk shrew), musk beetle, African civet, North America alligators also produce chemicals responsible for a musky smell. Among the plants producing similar aromas we have Garden Angelica, Abelmosk (Ambrette seeds, Musk mallow), muskflower, muskwood.
Here are some perfumes featuring more or less pronouned musk accord:
- Coty Wild Musk
- Nasomatto Silver Musk
- DS & Durga Poppy Rouge
- Amouage Musk Abyadh
- Kiehl’s Original Musk
- Prada Candy
- Dior Cologne Royale
- Le Labo Musc 25
I almost forgot to mention that musk, natural or synthetic is a great perfume fixative.
PS. I will be traveling between Friday and Sunday and I will not likely be able to respond to the comments quickly if at all. In case I won’t be able to see you at the weekend (will be relying on my phone and free wi-fi connection only) I’m wishing you all a good time and I’ll see you next week.