Rose oxide is an organic compound

Organic compound

An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...

 of the pyran

Pyran

In chemistry, a pyran, or oxine, is a six-membered heterocyclic, non-aromatic ring, consisting of five carbon atoms and one oxygen atom and containing two double bonds. The molecular formula is C5H6O. There are two isomers of pyran that differ by the location of the double bonds...

 class and the monoterpene

Monoterpene

Monoterpenes are a class of terpenes that consist of two isoprene units and have the molecular formula C10H16. Monoterpenes may be linear or contain rings...

 class and a fragrance found in roses

Rose

A rose is a woody perennial of the genus Rosa, within the family Rosaceae. There are over 100 species. They form a group of erect shrubs, and climbing or trailing plants, with stems that are often armed with sharp prickles. Flowers are large and showy, in colours ranging from white through yellows...

 and rose oil

Rose oil

Rose oil, meaning either rose otto or rose absolute, is the essential oil extracted from the petals of various types of rose...

. The compound has both a cis- and a trans-isomer, each with a (+)- and (−)-stereoisomer, but only the (−)-cis isomer (odor treshhold 0.5 ppb) is responsible for the typical rose (floral green) fragrance. Rose oxide also contributes to the flavor of some fruits such as lychee

Lychee

The lychee is the sole member of the genus Litchi in the soapberry family, Sapindaceae. It is a tropical and subtropical fruit tree native to Southern China and Southeast Asia, and now cultivated in many parts of the world...

 and Gewürztraminer

Gewürztraminer

Gewürztraminer is an aromatic wine grape variety that performs best in cooler climates. It is sometimes referred to colloquially as Gewürz, and in French it is written '...

.

Rose oxide is produced industrially beginning with photooxygenation

Photooxygenation

A photooxygenation is a light-induced oxidation reaction in which molecular oxygen is incorporated into the product. Initial research interest in photooxygenation reactions arose from Oscar Raab's observations in 1900 that the combination of light, oxygen and photosensitizers is highly toxic to cells...

 of citronellol

Citronellol

Citronellol, or dihydrogeraniol, is a natural acyclic monoterpenoid. Both enantiomers occur in nature. -Citronellol, which is found in citronella oils, including Cymbopogon nardus , is the more common isomer. -Citronellol is found in the oils of rose and Pelargonium geraniums.Citronellol is...

 to give the allyl hydroperoxide which is then reduced with sodium sulfite

Sodium sulfite

Sodium sulfite is a soluble sodium salt of sulfurous acid. It is a product of sulfur dioxide scrubbing, a part of the flue gas desulfurization process...

 to provide the diol

Diol

A diol or glycol is a chemical compound containing two hydroxyl groups A geminal diol has two hydroxyl groups bonded to the same atom...

. Ring-closure with sulfuric acid

Sulfuric acid

Sulfuric acid is a strong mineral acid with the molecular formula . Its historical name is oil of vitriol. Pure sulfuric acid is a highly corrosive, colorless, viscous liquid. The salts of sulfuric acid are called sulfates...

forms both the cis- and trans-isomers in equal amounts.