Menthone

Structural formula
	Both enantiomers of menthone
General
Surname	Menthone
other names	2-propyl- (2) -5-methyl-cyclohexanone; 2-isopropyl-5-methylcyclohexanone;
Molecular formula	C 10 H 18 O
Brief description	colorless liquid, (-) - menthone has a faint mint odor
External identifiers / databases
EC number	201-941-1
ECHA InfoCard	100.001.765
Wikidata	Q54015201
properties
Molar mass	154.25 g mol −1
Physical state	liquid
density	0.89 g cm −3 (-) - menthone
Melting point	−6 ° C (-) - menthone
boiling point	207-210 ° C (-) - menthone
Vapor pressure	67 Pa (20 ° C) (-) - menthone
solubility	308 mg l −1 in water
Refractive index	1.451
safety instructions
GHS labeling of hazardous substances Caution
H and P phrases	H: 315-317
	P: 261-264-272-280-302 + 352-333 + 313
	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

Menthone (stress on the second syllable: Menth o n ) is a monocyclic monoterpene - ketone .

Representative

There are two enantiomeric menthones, the (2 S , 5 R ) - (-) - menthone [also known as (-) - menthone for short] and the (2 R , 5 S ) - (+) - menthone [also known as (+) - menthone denotes].

In menthone, the substituents on the cyclohexanone ring are arranged in a trans position; the isomers with a cis configuration are referred to as isomenthone .

Enantiomers of menthone
Surname	(-) - menthone	(+) - menthone
other names	(2 S , 5 R ) - (-) - menthone L- menthone	(2 R , 5 S ) - (+) - menthone D- menthone
Structural formula
CAS number	14073-97-3	3391-87-5
CAS number	89-80-5 (mixture of isomers)
EC number	237-926-1	222-227-6
ECHA info card	100.034.464	100.020.207
PubChem	26447	443159
Wikidata	Q424902	Q27105203

Occurrence

(-) - Menthon is found in geranium oil and peppermint oil .

Peppermint ( Mentha × piperita ) contains (-) - menthone.

Together with (-) - isomenthone, (+) - menthone is the main component of beech leaf oil ( Agathosma betulina ).

Extraction and presentation

Menthone can be produced by oxidizing menthol . The simplest oxidation is the reaction with potassium dichromate in sulfuric acid .

properties

Physical Properties

Menthon is a colorless liquid with a mint odor. The compound solidifies at −6 ° C and boils at around 210 ° C at normal pressure. The racemate boils at 207 ° C. Both enantiomers are only sparingly soluble in water at 308 mg · l ⁻¹ but readily soluble in ethanol and have a density of 0.89 g · cm ⁻³ . The flash point of the enantiomers is 72 ° C, that of the racemate is 69 ° C.

Analytics

Reliable qualitative and quantitative determination of menthone is achieved after appropriate sample preparation by coupling gas chromatography with mass spectrometry in conjunction with headspace analysis . In forensic analysis, the use of alcoholic beverages containing menthone can also be reliably determined.

Web links

Fragrance Lexicon: Menthon

Individual evidence

↑ Entry on Menthon. In: Römpp Online . Georg Thieme Verlag, accessed on December 29, 2014.

↑ ^a ^b ^c Menthon data sheet (PDF) from Carl Roth , accessed on December 14, 2010.

↑ ^a ^b Menthon data sheet at Sigma-Aldrich , accessed on December 14, 2010 ( PDF ).

↑ ^a ^b N. Ajisaka, K. Hara, K. Mikuni, K. Hara, H. Hashimoto: Effects of Branched cyclodextrin on the Solubility and Stability of Terpenes. In: Bioscience, Biotechnology, and Biochemistry . Volume 64, No. 4, 2000, pp. 731-734; doi: 10.1271 / bbb.64.731 .

↑ ^a ^b Entry on L-Menthan-3-one in the GESTIS substance database of the IFA , accessed on January 10, 2017(JavaScript required) .

↑ HC Brown, CP Garg: A simple procedure for the chromic acid oxidation of alcohols to ketones of high purity. In: J. Am. Chem. Soc. Volume 83, No. 13, 1961, pp. 2952-2953.

↑ K. Schulz, M. Bertau, K. Schlenz, S. Malt, J. Dressler, DW Lachenmeier: Headspace solid-phase microextraction-gas chromatography-mass spectrometry determination of the characteristic flavors menthone, isomenthone, neomenthol and menthol in serum samples with and without enzymatic cleavage to validate post-open alcohol drinking claims. In: Anal Chim Acta. Volume 646, No. 1-2, Jul 30, 2009, pp. 128-140. PMID 19523566

[roempp-1] Entry on Menthon. In: Römpp Online . Georg Thieme Verlag, accessed on December 29, 2014.