Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A Fragrance That Breaks the Rules

07.12.2012
Synthesis of a Spirocyclic Seco Structure of the Principal Vetiver Odorant Khusimone

Approximately one third of all fragrances on the market contain vetiver oil as a key ingredient, for which no synthetic odorant is commercially available. Instead it has to be distilled from the dried roots of vetiver grass.

To find out about the structural requirements of vetiver odorants, researchers in Switzerland devised a synthesis to a 7,8-seco-khusimone, which still contained all the structural features held responsible for the vetiver odour. As they report in the European Journal of Organic Chemistry, however, the final product displayed none of the expected olfactory characteristics, thus proving the vetiver rule wrong.

Vetiver oil has a distinct and characteristic suave and sweet woody-earthy odour with additional green grapefruit and rhubarb-type facets. In perfumery it is often used to provide the woody base note in combination with rather inexpensive bergamot oil, or its synthetic counterparts, which provides a fresh citrus component.

Currently, there is no synthetic vetiver perfumery material available commercially. This lack of availability is partially due to the complex sesquiterpene nature of its constituents, and partially due to the lack of consensus as to which constituents contribute to its characteristic odour. One component for which there is consensus is (¨C)-khusimone, which forms only up to 2% of the essential oil, but does present a typical vetiver odour and is, so far, the only genuine natural lead structure.

Syntheses of related structures led to the development of a vetiver rule, which postulates that the woody odour of vetiver is a result of the presence of an ¦Á-branched carbonyl osmophore at a specific distance from a bulky group, with an overall dimension of 13¨C15 carbon atoms. Philip Kraft and Natacha Denizot (Givaudan, Switzerland) thus decided to apply this vetiver rule to the genuine lead structure khusimone itself in order to design a new vetiver odorant with even improved olfactory properties, and in addition an easier synthetic access.

The target structure, 7,8-seco-khusimone, was obtained as a mixture of diastereomers in a 10-step sequence starting from commercially available allyl alcohol and isovaleric acid. A key advantage of the sequence is that it fairly easily allows further modifications of the target structure. Although the desired compound was synthesised successfully it was 10 times less intense than (¨C)-khusimone and displayed a floral, rosy, green, germanium-like odour with no woody or vetiver character. Kraft and Denizot, therefore, conclude that the vetiver rule has been proved wrong, or at least that the structural requirements are more complex than first suggested.
Author: Philip Kraft, Givaudan Schweiz AG, D¨¹bendorf (Switzerland), mailto:philip.kraft@givaudan.com
Title: Synthesis of a Spirocyclic Seco Structure of the Principal Vetiver Odorant Khusimone

European Journal of Organic Chemistry , 2013, No. 1, Permalink to the article: http://dx.doi.org/10.1002/ejoc.201201318

Philip Kraft | Wiley-VCH
Further information:
http://www.wiley-vch.de

More articles from Life Sciences:

nachricht More genes are active in high-performance maize
19.01.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht How plants see light
19.01.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Let the good tubes roll

19.01.2018 | Materials Sciences

How cancer metastasis happens: Researchers reveal a key mechanism

19.01.2018 | Health and Medicine

Meteoritic stardust unlocks timing of supernova dust formation

19.01.2018 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>