p -Menthan

Structural formula
General
Surname	p -Menthan
other names	1-methyl-4-isopropylcyclohexane; 4-isopropyl-1-methyl-cyclohexane;
Molecular formula	C 10 H 20
Brief description	Liquid smelling like fennel
External identifiers / databases
EC number	202-790-4
ECHA InfoCard	100.002.537
PubChem	7459
Wikidata	Q2043490
properties
Molar mass	140.27 g mol −1
Physical state	liquid
density	0.79 g cm −3 (20 ° C, trans form); 0.81 g cm −3 (20 ° C, cis -form);
boiling point	170.6 ° C ( trans form); 172 ° C ( cis -form);
solubility	almost insoluble in water (0.62 mg l −1 at 20 ° C)
Refractive index	1.4369 ( trans form); 1.4434 ( cis -form);
safety instructions
H and P phrases	H: 226-315-304
	P: 210-403 + 235-301 + 310-331-501
	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

p- menthane ( para- menthane ) is the common name of the monocyclic chemical compound 1-methyl-4-isopropyl-cyclohexane from the group of monoterpenes . para- menthane forms the backbone of many naturally occurring terpenes such as terpinene , limonene , phellandrene and terpinolene .

Occurrence

In contrast to other terpenes , menthane occurs only rarely in nature, but has been found in the essential fruit oil of the tree Eucalyptus globulus .

Extraction and presentation

Menthane can be produced by catalytic hydrogenation of the aromatic p -cyymol or the unsaturated compounds limonene and α-terpinene .

properties

Menthane is a colorless liquid with a fennel or mint-like odor. It belongs to the terpene - hydrocarbons . In addition to the para-menthane also are ortho and meta (isomers o - and m -Menthan) known. Only the p However -Menthan there are two stereoisomers , the cis - p -Menthan and trans - p -Menthan. In the cis form, the two substituents point to the front, in the trans form one points towards the front and one towards the back.

cis and trans isomer of p- menthane
a: substituent is axial , e: substituent is equatorial

use

Menthane or the more effective derivative para- menthane-3,8-diol (PMD) is used as a repellent against ticks and insects such as mosquitoes and industrially as an intermediate in the synthesis of p- menthane hydroperoxide , a catalyst for radical polymerization .

Individual evidence

↑ ^a ^b ^c Entry on p-menthane. In: Römpp Online . Georg Thieme Verlag, accessed on July 7, 2014.
^ ^A ^b ^c ^d R. T. O'Connor, LA Goldblatt: Correlation of Ultraviolet and Infrared Spectra of Terpene Hydrocarbons , in: Anal. Chem. 1954, 26, pp. 1726-1737; doi: 10.1021 / ac60095a014 .
↑ ^a ^b ^c Entry on 1-isopropyl-4-methylcyclohexane in the GESTIS substance database of the IFA , accessed on January 10, 2017(JavaScript required) .
↑ Repellants: Protected against ticks, mosquitoes and the like . In: Pharmaceutical newspaper . 2013, No. 24.

[roempp-1] Entry on p-menthane. In: Römpp Online . Georg Thieme Verlag, accessed on July 7, 2014.

[oc-2] A ^b ^c ^d R. T. O'Connor, LA Goldblatt: Correlation of Ultraviolet and Infrared Spectra of Terpene Hydrocarbons , in: Anal. Chem. 1954, 26, pp. 1726-1737; doi: 10.1021 / ac60095a014 .

[GESTIS-3] Entry on 1-isopropyl-4-methylcyclohexane in the GESTIS substance database of the IFA , accessed on January 10, 2017(JavaScript required) .

[4] Repellants: Protected against ticks, mosquitoes and the like . In: Pharmaceutical newspaper . 2013, No. 24.