Karvon
Carvone is a terpenoid that has two mirror-image forms, or enantiomers. R-(−)-carvone has the sweetish minty smell of spearmint leaves, while S-(+)-carvone has a spicy aroma with notes of rye.
- Type
- Sirovina
- Olfactive family
- Aromatični
- Source
- essential oils of caraway, spearmint and dill
- Chemical class
- ketone (terpenoid)
Miris
Detaljno
Zanimljivosti
S-(+)-Carvone is used to prevent premature sprouting of potatoes during storage and is marketed in the Netherlands for this purpose under the name Talent. Squirrel monkeys have also been found to be able to discriminate between carvone enantiomers.
Dobijanje i hemija
Način dobijanja
L-carvone is produced commercially through either a natural or a synthetic process. It can be extracted from the essential oils of plants such as caraway, dill and spearmint. The oils are obtained through steam distillation, and L-carvone is then isolated using various chemical processes. D-carvone is usually prepared by fractional distillation of oil of caraway, and also from dillseed and dillweed oils. In the past, (+)- and (−)-carvones were isolated by fractional distillation of caraway oil and spearmint oil, respectively. L-carvone can also be synthesised chemically from limonene, a more abundant and cost-effective starting material. Carvones are now prepared synthetically, with limonenes as the preferred starting materials that are converted into the corresponding optically active carvones. Since optical rotation is reversed in the process, (+)-limonene is the starting material for (−)-carvone. The preferred industrial method uses the selective addition of nitrosyl chloride to the endocyclic double bond of limonene. If a lower aliphatic alcohol is used as solvent, limonene nitrosochloride is obtained in high yield. It is converted into carvone oxime by elimination of hydrogen chloride in the presence of a weak base. Acid hydrolysis in the presence of a hydroxylamine acceptor, such as acetone, yields carvone. An alternative process for the production of (−)-carvone starts from (+)-limonene 1,2-epoxide, whose regioselective rearrangement leads to (−)-carveol. (−)-Carveol is subsequently oxidized to (−)-carvone by an Oppenauer oxidation or by dehydrogenation in the presence of special catalysts.
- Formula
- C₁₀H₁₄O
- CAS
- 99-49-0
- Botanički naziv
- Mentha spicata (spearmint) / Carum carvi (caraway)
- Izgled
- Clear, colorless liquid
- Jačina mirisa
- Srednji
- Trajnost
- 24 hours at 100%
- Sinonimi
- carvol, 2-methyl-5-isopropenyl-2-cyclohexenone, 5-isopropenyl-2-methylcyclohex-2-en-1-one, 1-methyl-4-isopropenyl-6-cyclohexen-2-one
Restricted — IFRA Standard « Carvone » (Amendment 49): limits in the finished product are Category 1 0.20 %, Category 2 0.060 %, Category 3 0.020 %, Category 4 0.59 %, Category 5A 0.20 %, Category 5B 0.039 %, Category 5C 0.059 %, Category 5D 0.013 %, Category 6 0.66 %, Category 7A 0.039 %, Category 7B 0.039 %, Category 8 0.013 %, Category 9 0.18 %, Category 10A 0.18 %, Category 10B 0.43 %, Category 11A 0.013 %, Category 11B 0.013 %, Category 12 17 %
- Tačka ključanja
- 231 °C
- Tačka topljenja
- 25.2 °C
- Tačka paljenja
- 192.00 °F TCC (88.89 °C)
- Relativna gustina
- 0.956 to 0.960 @ 25 °C
- Indeks prelamanja
- 1.495 to 1.499 @ 20 °C
U parfemima
L-carvone is used as a fragrance in personal care products such as soaps, cosmetics and perfumes, and in consumer products such as air fresheners. R-(−)-Carvone is also used for air freshening products. Carvone serves as a perfuming and fragrance ingredient in cosmetics. It demands great skill and experience in application. It seems to be a very good and compatible companion to rose oxide and the jasmone chemicals. Carvone is used in flavoring, liqueurs, perfumery and soaps.
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