Carvone, (-)- (6485-40-1) Physical and Chemical Properties
Carvone, (-)-
A naturally occurring monoterpene ketone supplied as the (-)-enantiomer for use in flavor, fragrance and analytical formulations.
| CAS Number | 6485-40-1 |
| Family | Monoterpene ketones |
| Typical Form | Colorless to pale liquid |
| Common Grades | BP, EP, FCC, JP |
(-)-Carvone is a monoterpenoid ketone belonging to the cyclohexenone structural class; its molecular formula is \(\ce{C10H14O}\). Structurally it is a substituted 2-cyclohexenone bearing an isopropenyl and a methyl substituent and one defined stereocenter (the natural levo enantiomer, designated (5R) in the IUPAC name). The conjugated cyclohexenone motif gives a modestly polar carbonyl function adjacent to a C=C bond while the remainder of the molecule is hydrocarbon-rich; this combination yields intermediate polarity, low topological polar surface area (\(\mathrm{TPSA}=17.1\)), and limited hydrogen-bonding capacity (one acceptor, zero donors).
Chemically, (-)-carvone behaves as a neutral, lipophilic terpene ketone. Its partitioning favors organic phases (experimental logP ≈ 2.71; computed XLogP3 ≈ 2.4), making it readily soluble in organic solvents and oils and only sparingly soluble in water. The carbonyl and alkene functionality are susceptible to common terpene-type transformations (e.g., hydrogenation, allylic oxidation, conjugate addition), while the molecule is generally stable toward hydrolysis under neutral conditions. As a flavour and fragrance ingredient, as well as a plant growth regulator active, its sensory and biological activity is stereochemistry-dependent: the (−)-enantiomer produces a spearmint-like odour and is the enantiomer predominantly used in food and fragrance applications.
Common commercial grades reported for this substance include: BP, EP, FCC, JP.
Basic Physical Properties
Density
Reported experimental values: 0.956-0.960 (units not specified in the available numerical description). This range is consistent with typical monoterpene liquids whose densities are close to \(\sim0.9!-!1.0\) g·mL\(^{-1}\) at ambient temperature; density influences formulation dosing and phase behavior in oil-based systems.
Melting Point
Reported experimental value: < 15 \(\,^\circ\mathrm{C}\). As a liquid at ambient room temperature for typical storage conditions, (-)-carvone has a low melting point and will solidify only at temperatures below typical refrigerated storage.
Boiling Point
Reported experimental value: 227.00 to 230.00 \(\,^\circ\mathrm{C}\) @ 760.00 \(\mathrm{mm\ Hg}\). The relatively high atmospheric boiling point reflects low vapor pressure for a small terpene ketone and corresponds to moderate volatility at elevated temperatures; distillation or vacuum fractionation is typically used for purification.
Vapor Pressure
No experimentally established value for this property is available in the current data context.
Flash Point
No experimentally established value for this property is available in the current data context.
Chemical Properties
Solubility and Phase Behavior
Reported solubility: 1.31 \(\mathrm{mg}\,\mathrm{mL}^{-1}\) at 25 \(\,^\circ\mathrm{C}\). Additional qualitative solubility notes: soluble in propylene glycol and most fixed oils; insoluble in glycerol; miscible with alcohol (e.g., ethanol). A formulation example reports "1 ml in 2 ml 70% alcohol (in ethanol)". These data indicate limited aqueous solubility but ready solubility in common cosmetic and flavoring solvents and carriers; solubility in propylene glycol and oils facilitates incorporation into emulsions and oil-based matrices.
Reactivity and Stability
The compound contains an α,β‑unsaturated ketone (conjugated enone) which is moderately electrophilic; it can undergo conjugate (1,4-) additions, hydrogenation of the C=C bond, and oxidation under strong conditions. Under normal storage and handling (dark, dry, moderate temperatures) it is chemically stable; however, as a fragrance/volatile organic ingredient it can oxidize on prolonged air exposure producing degradation products that may increase sensitization potential. Standard chemical precautions apply: exclude strong oxidants, minimize prolonged exposure to air and light, and control elevated temperatures to reduce evaporation and decomposition.
Thermodynamic Data
Standard Enthalpies and Heat Capacity
No experimentally established value for this property is available in the current data context.
Molecular Parameters
Molecular Weight and Formula
Molecular formula: \(\ce{C10H14O}\).
Molecular weight (computed): 150.22.
Other computed descriptors: exact/monoisotopic mass = 150.104465066; heavy atom count = 11; formal charge = 0.
LogP and Polarity
Computed XLogP3‑AA: 2.4.
Reported experimental LogP: 2.71.
Topological polar surface area (TPSA): 17.1.
Hydrogen-bond donor count: 0; hydrogen-bond acceptor count: 1; rotatable bond count: 1.
These values indicate moderate lipophilicity and low polarity consistent with ready partitioning into organic phases and limited aqueous solubility.
Structural Features
IUPAC name (computed): (5R)-2-methyl-5-prop-1-en-2-ylcyclohex-2-en-1-one. The molecule is a C10 monoterpenoid with a conjugated cyclohexenone core, one stereocenter (defined atom stereocenter count = 1), and an isopropenyl substituent. The enone motif imparts reactivity typical of α,β‑unsaturated ketones (conjugate addition, reduction), while the isopropenyl and methyl substituents provide steric and electronic features that shape odorant and biological interactions.
Key structural identifiers: SMILES: CC1=CC[C@H](CC1=O)C(=C)C; InChI: InChI=1S/C10H14O/c1-7(2)9-5-4-8(3)10(11)6-9/h4,9H,1,5-6H2,2-3H3/t9-/m1/s1; InChIKey: ULDHMXUKGWMISQ-SECBINFHSA-N. (Presented here as the canonical stereochemical descriptors for analytical and procurement use.)
Identifiers and Synonyms
Registry Numbers and Codes
- CAS: 6485-40-1
- European Community (EC) Number: 229-352-5
- UNII: 5TO7X34D3D
- FEMA Number: 2249
- ChEBI ID: CHEBI:15400
- ChEMBL ID: CHEMBL2229268
- DSSTox Substance ID: DTXSID7041413
- KEGG ID: C01767
- HMDB ID: HMDB0035089
- InChI:
InChI=1S/C10H14O/c1-7(2)9-5-4-8(3)10(11)6-9/h4,9H,1,5-6H2,2-3H3/t9-/m1/s1 - InChIKey:
ULDHMXUKGWMISQ-SECBINFHSA-N - SMILES:
CC1=CC[C@H](CC1=O)C(=C)C
Synonyms and Structural Names
Depositor-supplied synonyms include (selection):
(-)-Carvone; (R)-(-)-Carvone; l-Carvone; L(-)-Carvone; Levo-carvone; (4R)-Carvone; Carvone, (-)-; (-)-p-Mentha-6,8-dien-2-one; (5R)-2-methyl-5-(prop-1-en-2-yl)cyclohex-2-en-1-one; (R)-Carvone; R-(-)-Carvone; l-1-Methyl-4-isopropenyl-6-cyclohexen-2-one; (R)-p-mentha-6,8-dien-2-one. (A larger set of synonyms and older/deprecated names is available in supplier and regulatory nomenclature lists.)
Industrial and Commercial Applications
Representative Uses and Industry Sectors
(-)-Carvone is widely used as a flavouring and fragrance ingredient, supplying a spearmint-type aroma in confectionery, oral care, and personal-care products. It is classified within flavoring agent lists and is present in cosmetics and fragrance formulations, subject to standard use restrictions for sensitizing fragrances. It is also registered as a plant growth regulator active substance in agrochemical contexts (l‑carvone listed among pending active substances in certain regulatory datasets). Production and processing sectors include flavour and fragrance manufacture, soap and cosmetic preparation, and pesticide/agrochemical manufacturing.
Role in Synthesis or Formulations
In formulations, (-)-carvone is used as a neat fragrance compound or as part of complex essential oil fractions; it is miscible with ethanol and many cosmetic solvents (e.g., propylene glycol, fixed oils). In synthetic chemistry, the conjugated enone allows for selective hydrogenation, conjugate addition, and reductive transformations to produce saturated ketones or alcohols; stereochemistry is important for sensory properties and biological activity.
If further concise application summaries are required specific to a particular industrial process or formulation, selection is typically based on the compound’s olfactory properties, volatility, and solubility profile described above.
Safety and Handling Overview
Acute and Occupational Toxicity
Aggregated hazard classifications indicate: Skin sensitisation — Category 1 (H317: May cause an allergic skin reaction); in many notifications Acute Toxicity (oral) — Category 4 (H302: Harmful if swallowed); Flammable liquids — Category 4 (H227: Combustible liquid). Toxicological assessments summarized for flavouring use report no genotoxicity concern and a No Expected Sensitisation Induction Level (NESIL) applied in risk characterization for dermal exposure; margin of exposure considerations for repeated dose and reproductive endpoints have been evaluated in safety assessments.
Practically, (-)-carvone is a known fragrance allergen for susceptible individuals; workplace and product exposures should be controlled to minimize dermal contact and inhalation at high concentrations. For occupational settings, use of appropriate personal protective equipment (gloves, eye protection), good ventilation, and measures to avoid skin contamination are recommended.
Storage and Handling Considerations
Store in a cool, well-ventilated area away from ignition sources and strong oxidizers. Keep containers tightly closed to minimize evaporation and oxidation. Minimize prolonged air and light exposure to reduce formation of oxidation products that can increase sensitization potential. For detailed hazard, transport and regulatory information, users should refer to the product-specific Safety Data Sheet (SDS) and local legislation.
For emergency response, treat as a combustible liquid with potential to cause skin sensitization; avoid release to drains and the environment. Use standard spill control measures for organic liquids and collect for proper disposal.
