Phellandrene

The phellandrene are a group of chemical compounds , more specifically from monoterpene - hydrocarbons . They are colorless, oily liquids. They are part of essential oils .

Representative

The structure isomeric α-Phellandren and β-Phellandren each have a stereogenic center. Hence there are two enantiomers each of α-phellandren and β-phellandren:

Phellandrene
Surname	( R ) -α-Phellandren	( S ) -α-Phellandren	( R ) -β-Phellandren	( S ) -β-Phellandren
Structural formula
other names	( R ) -2-methyl-5- (1-methylethyl) -1,3-cyclohexadiene	( S ) -2-methyl-5- (1-methylethyl) -1,3-cyclohexadiene	( R ) -3-Methylene-6- (1-methylethyl) cyclohexene	( S ) -3-Methylene-6- (1-methylethyl) cyclohexene
CAS number	4221-98-1	2243-33-6	6153-17-9	6153-16-8
	99-83-2 ( RS ) -α-Phellandren		555-10-2 ( RS ) -β-Phellandren
	1329-99-3 (unspec.)
EC number	224-167-6
	202-792-5		209-081-9
	215-532-0
ECHA info card	100,021,971
	100.002.538		100.008.257
	100.014.121
PubChem	442482	443160	443161	442484
	7460		11142
Molecular formula	C 10 H 16
Molar mass	136.24 g mol −1
Physical state	liquid
Brief description	colorless to yellowish liquid
boiling point	171-172 ° C		171-172 ° C
density	0.84 to 0.85 g cm −3 (20 ° C)
solubility	almost insoluble in water, soluble in ether
Refractive index	1.471 (25 ° C)		1.4788 (20 ° C)
GHS labeling	danger		no classification available
H and P phrases	226-315-319-334-335		see above
	no EUH phrases		see above
	261-305 + 351 + 338-342 + 311		see above

The 1: 1 mixture of ( R ) -α-Phellandren and ( S ) -α-Phellandren is ( RS ) -α-Phellandren, a racemate . Analogously, ( RS ) -β-Phellandren is a racemate of ( R ) -β-Phellandren and ( S ) -β-Phellandren.

Occurrence

Caraway seeds are rich in essential oils.

They are found in cumin , fennel , eucalyptus oil , field fennel and dill , among others .

properties

Enantiomeric terpenes usually have a different odor because the olfactory receptors in humans are themselves chiral . α-Phellandren has a spicy, mint-like smell, β-Phellandren smells mint-like, and both smell of turpentine . The odor threshold of β-Phellandren is 700  ppb .

The phellandrenes belong to the prophaptens due to the combination of six-membered rings and conjugated double bonds , i.e. H. their oxidation products in the air or reaction products in contact with the skin are allergenic.

Individual evidence

1. ↑ ^{a b c d e} The Merck Index . An Encyclopaedia of Chemicals, Drugs and Biologicals. 14th edition, 2006, ISBN 978-0-911910-00-1 , p. 1243.
2. ↑ Data sheet α-Phellandren (PDF) from Merck , accessed on January 21, 2019.
3. ↑ ^{a b} David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-420.
4. ↑ ^{a b} Data sheet α-Phellandrene from Sigma-Aldrich , accessed on February 5, 2018 ( PDF ).
5. ↑ MA Bergstrom et al .: Conjugated dienes as prohaptens in contact allergy: in vivo and in vitro studies of structure-activity relationships, sensitizing capacity, and metabolic activation. In: Chemical Research in Toxicology . Volume 19, 2006, pp. 760-769, PMID 16780354 .