2-Hydroxy-3,4-dimethylcyclopent-2-en-1-one

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  • Identifiers

    CAS number
    21835-00-7

    Molecular formula
    C7H10O2

    SMILES
    CC1CC(=O)C(=C1C)O

  • Odor profile

    Fragrance
    Caramellic 84.13%
    Sweet 68.61%
    Burnt 64.3%
    Coffee 40.29%
    Roasted 34.67%
    Phenolic 34.46%
    Spicy 27.06%
    Nutty 26.62%
    Malty 25.34%
    Sharp 22.0%

     

    Flavor
    Sweet 66.61%
    Caramel 62.56%
    Maple 56.48%
    Sugar 39.28%
    Smoky 34.56%
    Tobacco 33.08%
    Phenolic 32.86%
    Candy 32.63%
    Spice 30.12%
    Minty 28.14%

     

    Odor impact est.
    High

  • Properties

    XLogP3-AA
    0.6

    pKa est.
    8.36 (weak base)

    Molecular weight
    126.15 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Very slow

    Boiling point est.
    258°C

    Flash point

    • 93.87 ˚C est.

  • Synonyms

    • 21835-00-7
    • 2-Hydroxy-3,4-dimethyl-2-cyclopenten-1-one
    • 2-Hydroxy-3,4-dimethylcyclopent-2-en-1-one
    • 2-Cyclopenten-1-one, 2-hydroxy-3,4-dimethyl-
    • 3,4-Dimethyl-2-hydroxycyclopent-2-en-1-one
    • 2-hydroxy-3,4-dimethyl-cyclopent-2-en-1-one
    • EINECS 244-604-4
    • DTXSID5051864
    • MFCD08282774
    • 2-hydroxy-3,4-dimethylcyclopent-2-enone
    • hydroxydimethyl cyclopentenone
    • SCHEMBL3891520
    • DTXCID8030423
    • BBL103101
    • STL556911
    • AKOS006289607
    • 3,4-Dimethyl-2-hydroxy-2-cyclopentenone
    • DB-270034
    • 3,4-Dimethyl-2-hydroxy-2-cyclopenten-1-on
    • CS-0336397
    • NS00021858
    • D93041

  • Applications

    2-Hydroxy-3,4-dimethylcyclopent-2-en-1-one (CAS 21835-00-7) is typically discussed as an odorant and a building block in fragrance chemistry, serving as a fragrance note precursor for more complex aroma molecules. In cosmetics and personal care formulations, it may be included as a fragrance ingredient to contribute specific scent profiles. In household cleaning products, it can function as a fragrance component to improve perceived freshness. It may also be evaluated as a flavor/aroma contributor in flavor science under controlled usage. As an intermediate, it is commonly considered for transformations that generate other fragrance-related compounds, with usage governed by local regulations and formulation limits.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 221.11
    methanol 396.96
    isopropanol 124.46
    water 69.78
    ethyl acetate 67.95
    n-propanol 143.85
    acetone 66.81
    n-butanol 119.6
    acetonitrile 81.25
    DMF 101.93
    toluene 10.94
    isobutanol 94.55
    1,4-dioxane 276.16
    methyl acetate 74.28
    THF 224.76
    2-butanone 58.89
    n-pentanol 87.68
    sec-butanol 90.02
    n-hexane 4.22
    ethylene glycol 123.87
    NMP 92.84
    cyclohexane 3.94
    DMSO 164.7
    n-butyl acetate 53.58
    n-octanol 51.2
    chloroform 148.51
    n-propyl acetate 44.03
    acetic acid 259.12
    dichloromethane 122.55
    cyclohexanone 80.11
    propylene glycol 78.84
    isopropyl acetate 47.66
    DMAc 74.53
    2-ethoxyethanol 202.51
    isopentanol 102.35
    n-heptane 4.25
    ethyl formate 65.53
    1,2-dichloroethane 73.45
    n-hexanol 85.45
    2-methoxyethanol 333.1
    isobutyl acetate 29.76
    tetrachloromethane 40.74
    n-pentyl acetate 51.28
    transcutol 518.02
    n-heptanol 62.92
    ethylbenzene 12.92
    MIBK 57.95
    2-propoxyethanol 174.11
    tert-butanol 151.33
    MTBE 72.02
    2-butoxyethanol 131.83
    propionic acid 118.42
    o-xylene 17.79
    formic acid 345.6
    diethyl ether 70.06
    m-xylene 17.61
    p-xylene 22.41
    chlorobenzene 31.24
    dimethyl carbonate 30.75
    n-octane 3.0
    formamide 406.13
    cyclopentanone 102.54
    2-pentanone 54.54
    anisole 49.84
    cyclopentyl methyl ether 63.39
    gamma-butyrolactone 159.44
    1-methoxy-2-propanol 179.73
    pyridine 71.41
    3-pentanone 35.32
    furfural 173.42
    n-dodecane 2.7
    diethylene glycol 211.96
    diisopropyl ether 26.09
    tert-amyl alcohol 117.7
    acetylacetone 75.66
    n-hexadecane 2.99
    acetophenone 49.02
    methyl propionate 51.14
    isopentyl acetate 58.02
    trichloroethylene 139.49
    n-nonanol 46.58
    cyclohexanol 59.05
    benzyl alcohol 54.92
    2-ethylhexanol 43.58
    isooctanol 53.73
    dipropyl ether 30.2
    1,2-dichlorobenzene 41.58
    ethyl lactate 36.54
    propylene carbonate 82.57
    n-methylformamide 134.84
    2-pentanol 73.54
    n-pentane 4.71
    1-propoxy-2-propanol 103.36
    1-methoxy-2-propyl acetate 74.64
    2-(2-methoxypropoxy) propanol 112.5
    mesitylene 15.74
    ε-caprolactone 94.28
    p-cymene 17.83
    epichlorohydrin 170.03
    1,1,1-trichloroethane 75.88
    2-aminoethanol 197.19
    morpholine-4-carbaldehyde 195.94
    sulfolane 174.68
    2,2,4-trimethylpentane 5.17
    2-methyltetrahydrofuran 110.75
    n-hexyl acetate 70.62
    isooctane 5.1
    2-(2-butoxyethoxy)ethanol 168.4
    sec-butyl acetate 31.02
    tert-butyl acetate 69.62
    decalin 4.48
    glycerin 160.91
    diglyme 260.75
    acrylic acid 117.71
    isopropyl myristate 29.51
    n-butyric acid 119.87
    acetyl acetate 48.9
    di(2-ethylhexyl) phthalate 35.97
    ethyl propionate 36.57
    nitromethane 253.87
    1,2-diethoxyethane 101.38
    benzonitrile 51.15
    trioctyl phosphate 28.68
    1-bromopropane 30.83
    gamma-valerolactone 191.21
    n-decanol 32.88
    triethyl phosphate 28.22
    4-methyl-2-pentanol 56.28
    propionitrile 52.09
    vinylene carbonate 81.41
    1,1,2-trichlorotrifluoroethane 157.52
    DMS 57.6
    cumene 16.48
    2-octanol 41.04
    2-hexanone 44.93
    octyl acetate 36.68
    limonene 21.22
    1,2-dimethoxyethane 185.5
    ethyl orthosilicate 28.89
    tributyl phosphate 32.27
    diacetone alcohol 106.91
    N,N-dimethylaniline 38.15
    acrylonitrile 71.68
    aniline 42.3
    1,3-propanediol 235.4
    bromobenzene 23.06
    dibromomethane 70.87
    1,1,2,2-tetrachloroethane 116.86
    2-methyl-cyclohexyl acetate 45.09
    tetrabutyl urea 36.53
    diisobutyl methanol 33.35
    2-phenylethanol 72.59
    styrene 13.04
    dioctyl adipate 41.0
    dimethyl sulfate 61.73
    ethyl butyrate 40.35
    methyl lactate 50.62
    butyl lactate 52.77
    diethyl carbonate 29.58
    propanediol butyl ether 111.24
    triethyl orthoformate 35.35
    p-tert-butyltoluene 17.22
    methyl 4-tert-butylbenzoate 73.35
    morpholine 238.62
    tert-butylamine 83.78
    n-dodecanol 24.07
    dimethoxymethane 111.4
    ethylene carbonate 64.44
    cyrene 85.85
    2-ethoxyethyl acetate 85.02
    2-ethylhexyl acetate 41.18
    1,2,4-trichlorobenzene 50.4
    4-methylpyridine 54.47
    dibutyl ether 34.76
    2,6-dimethyl-4-heptanol 33.35
    DEF 58.65
    dimethyl isosorbide 148.05
    tetrachloroethylene 109.39
    eugenol 88.67
    triacetin 68.82
    span 80 90.97
    1,4-butanediol 93.81
    1,1-dichloroethane 64.1
    2-methyl-1-pentanol 80.02
    methyl formate 98.44
    2-methyl-1-butanol 86.75
    n-decane 4.56
    butyronitrile 51.01
    3,7-dimethyl-1-octanol 48.3
    1-chlorooctane 20.53
    1-chlorotetradecane 8.05
    n-nonane 3.85
    undecane 3.4
    tert-butylcyclohexane 5.56
    cyclooctane 2.02
    cyclopentanol 76.69
    tetrahydropyran 101.95
    tert-amyl methyl ether 53.66
    2,5,8-trioxanonane 182.58
    1-hexene 15.17
    2-isopropoxyethanol 124.77
    2,2,2-trifluoroethanol 153.38
    methyl butyrate 48.63

    Scent© AI

1 4

IFRA standard 51

Recommendation
No restriction
Maximum acceptable concentrations in the finished product (%)
Category 1
Products applied to the lips
 No restriction Category 7A
Rinse-off products applied to the hair with some hand contact
 No restriction
Category 2
Products applied to the axillae
 No restriction Category 7B
Leave-on products applied to the hair with some hand contact
 No restriction
Category 3
Products applied to the face/body using fingertips
 No restriction Category 8
Products with significant anogenital exposure
 No restriction
Category 4
Products related to fine fragrance
 No restriction Category 9
Products with body and hand exposure, primarily rinse off
 No restriction
Category 5A
Body lotion products applied to the body using the hands (palms), primarily leave on
 No restriction Category 10A
Household care products with mostly hand contact
 No restriction
Category 5B
Face moisturizer products applied to the face using the hands (palms), primarily leave on
 No restriction Category 10B
Household care products with mostly hand contact, including aerosol/spray products (with potential leave-on skin contact)
 No restriction
Category 5C
Hand cream products applied to the hands using the hands (palms), primarily leave on
 No restriction Category 11A
Products with intended skin contact but minimal transfer of fragrance to skin from inert substrate without UV exposure
 No restriction
Category 5D
Baby Creams, baby Oils and baby talc
 No restriction Category 11B
Products with intended skin contact but minimal transfer of fragrance to skin from inert substrate with potential UV exposure
 No restriction
Category 6
Products with oral and lip exposure
 No restriction Category 12
Products not intended for direct skin contact, minimal or insignificant transfer to skin
 No restriction