5-methyl-2-hepten-4-one

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Structural formula
Structural formula of Filberton
(2 E , 5 S ) - (+) - stereoisomer
General
Surname 5-methyl-2-hepten-4-one
other names
  • (2 E ) -5-methyl-2-hepten-4-one ( IUPAC )
  • 5-methylhept-2-en-4-one
  • Filberton
  • TRANS-5-METHYL-2-HEPTEN-4-ONE ( INCI )
Molecular formula C 8 H 14 O
Brief description

In diluted solution, liquid smelling like hazelnut

External identifiers / databases
CAS number
  • 102322-83-8 [(+) - ( E )]
  • 81925-81-7 unspec.
  • 103070-07-1 [(+) - ( Z )]
  • 135910-94-0 (2 E , 5 R )
  • 122440-59-9 (2 E , 5 S )
EC number 600-299-3
ECHA InfoCard 100.133.148
PubChem 5362588
ChemSpider 4515100
Wikidata Q5448299
properties
Molar mass 126.20 g mol −1
Physical state

liquid

density

0.845 g cm −3

boiling point
  • 72 ° C (2 kPa)
  • 169-171 ° C
Refractive index

1.4440 (20 ° C)

safety instructions
GHS labeling of hazardous substances
02 - Highly / extremely flammable

Caution

H and P phrases H: 226
P: 210-280-240-241-303 + 361 + 353-501
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

5-Methyl-2-hepten-4-one is a chemical compound from the group of aliphatic enones . The trivial name Filberton is derived from English filberts - after St. Philibert for hazelnuts .

Occurrence

5-methyl-2-hepten-4-one is a natural product with low enantiomeric purity, which varies depending on its origin ( ee = 55–63%). In particular, the (+) - (2 E , 5 S ) isomer is the active principle of the hazelnut flavor.

Extraction and presentation

5-methyl-2-hepten-4-one can be obtained by a multi-stage reaction. For this purpose, ( S ) - (-) - 2-methylbutan-1-ol is oxidized to ( S ) - (+) - 2-methylbutanal , which is then oxidized with propynylithium to (4 R / 4 S , 5 S ) -5-methyl -hept-2-yn-4-ol is coupled. The stereoselective reduction with lithium aluminum hydride gives exclusively ( E , 4 R / 4 S , 5 S ) -5-methyl-2-hepten-4-ol, which is finally converted with manganese dioxide to ( S ) -5-methyl-2-hepten- 4-one is oxidized.

properties

5-Methyl-2-hepten-4-one is a liquid that smells like hazelnut in a dilute solution. Its odor threshold in water is 5  ppt .

use

The selective occurrence of 5-methyl-2-hepten-4-one in hazelnuts is used to control potential adulterations, for example for the detection of hazelnut oil in olive oil . The compound itself is used as a flavoring agent.

Individual evidence

  1. ↑ Entry on TRANS-5-METHYL-2-HEPTEN-4-ONE in the CosIng database of the EU Commission, accessed on March 18, 2020.
  2. ↑ a b c d e Johann Jauch, Dieter Schmalzing, Volker Schurig , Roland Emberger, Rudolf Hopp, Manfred Köpsel, Wilhelm Silberzahn, Peter Werkhoff: Isolation, synthesis and absolute configuration of Filberton, the active principle of the hazelnut aroma. In: Angewandte Chemie. 101, 1989, p. 1039, doi : 10.1002 / ange.19891010810 .
  3. ↑ Data sheet 5-Methyl-2-hepten-4-one, predominantly trans, 98%, FG from Sigma-Aldrich , accessed on August 6, 2018 ( PDF ).
  4. ↑ a b c d data sheet 5-Methyl-2-hepten-4-one, predominantly trans, 99% from AlfaAesar, accessed on August 6, 2018 ( PDF )(JavaScript required) .
  5. ↑ ML Ruiz del Castillo, E. Gómez Caballero, GP Blanch, M. Herraiz: Enantiomeric composition of filbertone in hazelnuts and hazelnut oils from different geographical origins. In: Journal of the American Oil Chemists' Society. 79, 2002, p. 589, doi : 10.1007 / s11746-002-0527-1 .
  6. ↑ a b entry on Filberton. In: Römpp Online . Georg Thieme Verlag, accessed on August 6, 2018.
  7. ↑ perfumerflavorist.com: Raw Material of the Week: Filbertone , accessed August 6, 2018.