Rose oxide

Structural formula
	Simplified structural formula without stereochemistry
General
Surname	Rose oxide
other names	Tetrahydro-4-methyl-2- (2-methyl-propenyl) -2 H -pyran; 4-methyl-2- (2-methyl-1-propenyl) tetrahydropyran; 4-methyl-2- (2-methyl-1-prop1-enyl) tetrahydropyran;
Molecular formula	C 10 H 18 O
Brief description	colorless liquid
External identifiers / databases
EC number	240-457-5
ECHA InfoCard	100.036.763
PubChem	27866
ChemSpider	25927
Wikidata	Q417155
properties
Molar mass	154.25 g · mol -1
Physical state	liquid
density	0.866 g cm −3
boiling point	86 ° C (20 mmHg)
solubility	slightly soluble in water
Refractive index	1.452
safety instructions
GHS labeling of hazardous substances Caution
H and P phrases	H: 315
	P: no P-phrases
Toxicological data	4.4 g kg −1 ( LD 50 , rat , oral )
	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

Rose oxide is a chemical compound from the group of pyrans and monocyclic monoterpenes , which is one of the main odorous substances in rose and rose oil . From a chemical point of view, rose oxide is a mixture of several isomeric forms.

Occurrence

Structural formulas of (-) - cis - and (-) - trans rose oxide with stereochemistry.

Rose oxide is a mixture of the isomeric cis and trans forms of the compound, whereby of course the (levorotatory) cis form is usually present and only (-) - cis rose oxide spreads the typical rose odor. It is responsible, among other compounds, for the characteristic scent of rose oil and geranium oil .

Rose 'Ave Maria' (1981, Kordes )

Of course, in addition to roses, rose oxide also occurs in some types of wine and in linden blossoms (and thus also in linden honey) and is responsible for the smell and taste. In addition, (-) - cis rose oxide occurs in essential oils, for example in geranium oil or in Bulgarian rose oil.

Rose oxide is also found in the defense secretion of some species of longhorn beetles .

Extraction and presentation

On an industrial scale, rose oxide can be obtained through the solar photooxidation of citronellol or from halohydrins or epoxides . In the more frequent synthesis starting from citronellol, this is converted into allyl hydroperoxides by introducing oxygen with UV light. These are reduced to diols using sodium sulfite . Only the diol formed from the tertiary allyl hydroperoxide can then be cyclized using dilute sulfuric acid. This results in (-) - cis or (-) - trans rose oxide in the same yield.

The microbial extraction of rose oxide is also possible.

properties

Rose oxide does not discolour and is relatively stable.

use

Rose oxide is used in the perfume industry for its strong geranium tip note, often in soaps, cosmetics, and other household products.

Individual evidence

↑ Rose Oxide 70. CAS-No. 16409-43-1. BASF , accessed May 5, 2017 .
↑ ^a ^b ^c ^d ^e Dieter Martinetz and Roland Hartwig: Pocket textbook of fragrances: a lexicon from A – Z. Harri Deutsch publishing house 1998; ISBN 3-8171-1539-3 ; P. 330ff.
↑ ^a ^b ^c ^d ^e data sheet Tetrahydro-4-methyl-2- (2-methyl-1-propenyl) -2H-pyran, ≥98%, mixture of cis and trans from Sigma-Aldrich , accessed on May 5, 2017 ( PDF ).
↑ Tetrahydro-4-methyl-2- (2-methylpropen-1-yl) pyran. FAO , accessed May 5, 2017 .
↑ ^a ^b entry on rose oxide. In: Römpp Online . Georg Thieme Verlag, accessed on May 5, 2017.
↑ Matthias Wüst: Wine - Quality is decided in nanograms: On the biochemistry of the varietal wine aroma. In: Chemistry in Our Time . 37, pp. 8-17, January 2003, doi: 10.1002 / ciuz.200390020 .
↑ 1.4. Primary flavors of linden honey compared to honeys of other origins. DFAL , 1989, archived from the original on May 16, 2004 ; Retrieved May 5, 2017 .
↑ Patent WO2001017983 : Method for producing rose oxide using halohydrins or epoxides. Published on March 15, 2001 , Inventors: Martin Demuth, Xuechao Xing, Kurt Schaffner. ‌
↑ Birgit Witte: Photochemical and thermal annulation reactions of conjugated alkynylcyclohex-2-enones . Hamburg 1999, DNB 95869883X , urn : nbn: de: gbv: 18-1223 (dissertation, University of Hamburg).
↑ Georg Schwedt: Beguiling fragrances, sensual aromas . Wiley-VCH, Weinheim 2012, ISBN 978-3-527-32045-5 ( limited preview in Google book search).

[1] Rose Oxide 70. CAS-No. 16409-43-1. BASF , accessed May 5, 2017 .

[Lexi-2] Dieter Martinetz and Roland Hartwig: Pocket textbook of fragrances: a lexicon from A – Z. Harri Deutsch publishing house 1998; ISBN 3-8171-1539-3 ; P. 330ff.

[sigma-3] ↑ ^a ^b ^c ^d ^e data sheet Tetrahydro-4-methyl-2- (2-methyl-1-propenyl) -2H-pyran, ≥98%, mixture of cis and trans from Sigma-Aldrich , accessed on May 5, 2017 ( PDF ).

[4] Tetrahydro-4-methyl-2- (2-methylpropen-1-yl) pyran. FAO , accessed May 5, 2017 .

[römpp-5] try on rose oxide. In: Römpp Online . Georg Thieme Verlag, accessed on May 5, 2017.

[6] Matthias Wüst: Wine - Quality is decided in nanograms: On the biochemistry of the varietal wine aroma. In: Chemistry in Our Time . 37, pp. 8-17, January 2003, doi: 10.1002 / ciuz.200390020 .

[7] 1.4. Primary flavors of linden honey compared to honeys of other origins. DFAL , 1989, archived from the original on May 16, 2004 ; Retrieved May 5, 2017 .

[8] Patent WO2001017983 : Method for producing rose oxide using halohydrins or epoxides. Published on March 15, 2001 , Inventors: Martin Demuth, Xuechao Xing, Kurt Schaffner. ‌

[9] Birgit Witte: Photochemical and thermal annulation reactions of conjugated alkynylcyclohex-2-enones . Hamburg 1999, DNB 95869883X , urn : nbn: de: gbv: 18-1223 (dissertation, University of Hamburg).

[10] Georg Schwedt: Beguiling fragrances, sensual aromas . Wiley-VCH, Weinheim 2012, ISBN 978-3-527-32045-5 ( limited preview in Google book search).