4-oxo-(E)-2-hexenal

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  • Identifiers

    CAS number
    2492-43-5

    Molecular formula
    C6H8O2

    SMILES
    CCC(=O)/C=C/C=O

    Safety labels

  • Odor profile

    Fragrance
    Pungent 63.02%
    Spicy 56.58%
    Caramellic 54.93%
    Sweet 44.53%
    Burnt 42.85%
    Nutty 42.57%
    Green 41.12%
    Radish 39.2%
    Buttery 39.01%
    Ethereal 37.38%

     

    Flavor
    Pungent 45.6%
    Mustard 30.92%
    Ethereal 28.82%
    Nutty 28.07%
    Caramel 27.71%
    Sweet 26.93%
    Almond 25.17%
    Butter 23.2%
    Garlic 22.55%
    Acidic 22.28%

     

    Odor impact est.
    High

  • Properties

    XLogP3-AA
    0.1

    pKa est.
    7.13 (neutral)

    Molecular weight
    112.13 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Moderately slow

    Boiling point est.
    221°C

    Flash point

    • 71.55 ˚C est.

  • Synonyms

    • 4-oxo-(e)-2-hexenal
    • RefChem:912756
    • (E)-4-oxohex-2-enal
    • 2492-43-5
    • (E)-4-Oxo-2-hexenal
    • (2E)-4-oxohex-2-enal
    • 4-OXOHEX-2-ENAL
    • 4-OXO-2-HEXENAL
    • 4-oxo-2E-Hexenal
    • 2-Hexenal, 4-oxo-, (E)-
    • 2-Hexenal, 4-oxo-, (2E)-
    • MFCD08690491
    • 4-OHE
    • (E)-4-Oxo-2-hexen-1-al
    • 4-Oxo-E-2-hexenal
    • 4-oxo-trans-2-hexenal
    • trans-4-Oxo-2-hexenal
    • trans-4-Ketohex-2-enal
    • 4MT6VG8ZKR
    • 4-oxidanylidenehex-2-enal
    • (2E)-4-Oxo-2-hexenal
    • trans-4-Oxohex-2-en-1-al
    • orb2564296
    • SCHEMBL1270742
    • CHEBI:76721
    • GVKYFODEMNCLGS-ONEGZZNKSA-N
    • DTXSID701315637
    • HY-N12851
    • LMFA06000120
    • AKOS006289522
    • SY343164
    • CS-1052889
    • NS00010557
    • Q27146302
    • 20697-55-6
    • OHE
    • 2492-43-5

  • Applications

    4-oxo-(E)-2-hexenal (CAS 2492-43-5) is primarily used as an odorant/fragrance ingredient in perfumery and cosmetics, and may serve as a scent component in household and cleaning products. It also functions as an intermediate in organic synthesis for industrial applications, including pharmaceutical and specialty chemical manufacturing. Its volatile, green-note character may lead to evaluation as a fragrance ingredient for consumer products beyond cosmetics, subject to formulation limits and local regulations. In research and development, it may be used as a precursor or semiochemical candidate in agricultural science.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 286.57
    methanol 505.34
    isopropanol 185.47
    water 4.86
    ethyl acetate 434.34
    n-propanol 179.31
    acetone 753.92
    n-butanol 171.37
    acetonitrile 811.12
    DMF 937.43
    toluene 127.68
    isobutanol 136.21
    1,4-dioxane 498.68
    methyl acetate 575.83
    THF 618.21
    2-butanone 542.04
    n-pentanol 138.55
    sec-butanol 157.69
    n-hexane 23.81
    ethylene glycol 94.68
    NMP 1087.53
    cyclohexane 22.48
    DMSO 1130.9
    n-butyl acetate 285.87
    n-octanol 83.98
    chloroform 639.04
    n-propyl acetate 273.77
    acetic acid 479.71
    dichloromethane 960.93
    cyclohexanone 535.51
    propylene glycol 69.15
    isopropyl acetate 209.52
    DMAc 872.41
    2-ethoxyethanol 280.1
    isopentanol 161.27
    n-heptane 17.83
    ethyl formate 318.19
    1,2-dichloroethane 582.04
    n-hexanol 131.72
    2-methoxyethanol 423.23
    isobutyl acetate 143.93
    tetrachloromethane 108.82
    n-pentyl acetate 154.72
    transcutol 1112.78
    n-heptanol 61.88
    ethylbenzene 101.26
    MIBK 179.3
    2-propoxyethanol 266.51
    tert-butanol 260.35
    MTBE 239.36
    2-butoxyethanol 146.89
    propionic acid 322.99
    o-xylene 115.84
    formic acid 225.83
    diethyl ether 224.1
    m-xylene 101.0
    p-xylene 140.48
    chlorobenzene 251.85
    dimethyl carbonate 174.96
    n-octane 10.23
    formamide 414.65
    cyclopentanone 819.02
    2-pentanone 346.88
    anisole 256.87
    cyclopentyl methyl ether 255.98
    gamma-butyrolactone 999.61
    1-methoxy-2-propanol 269.55
    pyridine 490.0
    3-pentanone 276.29
    furfural 752.48
    n-dodecane 10.55
    diethylene glycol 231.74
    diisopropyl ether 64.64
    tert-amyl alcohol 222.08
    acetylacetone 451.07
    n-hexadecane 11.95
    acetophenone 290.0
    methyl propionate 339.93
    isopentyl acetate 229.33
    trichloroethylene 1082.56
    n-nonanol 70.07
    cyclohexanol 156.22
    benzyl alcohol 185.85
    2-ethylhexanol 97.47
    isooctanol 55.16
    dipropyl ether 109.65
    1,2-dichlorobenzene 266.25
    ethyl lactate 114.21
    propylene carbonate 468.45
    n-methylformamide 481.26
    2-pentanol 115.23
    n-pentane 18.1
    1-propoxy-2-propanol 175.82
    1-methoxy-2-propyl acetate 233.56
    2-(2-methoxypropoxy) propanol 216.43
    mesitylene 66.85
    ε-caprolactone 490.83
    p-cymene 70.1
    epichlorohydrin 822.68
    1,1,1-trichloroethane 448.48
    2-aminoethanol 138.2
    morpholine-4-carbaldehyde 728.55
    sulfolane 1074.41
    2,2,4-trimethylpentane 17.85
    2-methyltetrahydrofuran 479.87
    n-hexyl acetate 228.91
    isooctane 11.53
    2-(2-butoxyethoxy)ethanol 271.05
    sec-butyl acetate 167.36
    tert-butyl acetate 219.49
    decalin 25.62
    glycerin 117.75
    diglyme 554.4
    acrylic acid 324.06
    isopropyl myristate 88.0
    n-butyric acid 332.31
    acetyl acetate 304.22
    di(2-ethylhexyl) phthalate 92.75
    ethyl propionate 233.89
    nitromethane 1156.36
    1,2-diethoxyethane 332.72
    benzonitrile 332.78
    trioctyl phosphate 63.46
    1-bromopropane 255.79
    gamma-valerolactone 785.62
    n-decanol 53.51
    triethyl phosphate 106.0
    4-methyl-2-pentanol 74.69
    propionitrile 378.25
    vinylene carbonate 416.6
    1,1,2-trichlorotrifluoroethane 430.98
    DMS 260.24
    cumene 74.44
    2-octanol 52.39
    2-hexanone 261.1
    octyl acetate 109.74
    limonene 97.24
    1,2-dimethoxyethane 498.31
    ethyl orthosilicate 94.09
    tributyl phosphate 99.16
    diacetone alcohol 251.65
    N,N-dimethylaniline 175.31
    acrylonitrile 585.7
    aniline 183.85
    1,3-propanediol 196.02
    bromobenzene 271.0
    dibromomethane 524.28
    1,1,2,2-tetrachloroethane 655.49
    2-methyl-cyclohexyl acetate 149.55
    tetrabutyl urea 129.55
    diisobutyl methanol 64.59
    2-phenylethanol 157.06
    styrene 138.86
    dioctyl adipate 140.29
    dimethyl sulfate 335.76
    ethyl butyrate 211.47
    methyl lactate 147.69
    butyl lactate 127.56
    diethyl carbonate 161.62
    propanediol butyl ether 159.26
    triethyl orthoformate 123.5
    p-tert-butyltoluene 64.55
    methyl 4-tert-butylbenzoate 177.83
    morpholine 507.98
    tert-butylamine 152.81
    n-dodecanol 43.14
    dimethoxymethane 344.86
    ethylene carbonate 323.02
    cyrene 207.21
    2-ethoxyethyl acetate 261.36
    2-ethylhexyl acetate 185.03
    1,2,4-trichlorobenzene 302.99
    4-methylpyridine 494.69
    dibutyl ether 132.54
    2,6-dimethyl-4-heptanol 64.59
    DEF 489.87
    dimethyl isosorbide 372.97
    tetrachloroethylene 425.62
    eugenol 192.17
    triacetin 275.43
    span 80 157.17
    1,4-butanediol 94.58
    1,1-dichloroethane 503.35
    2-methyl-1-pentanol 149.24
    methyl formate 410.24
    2-methyl-1-butanol 154.18
    n-decane 15.94
    butyronitrile 325.62
    3,7-dimethyl-1-octanol 95.47
    1-chlorooctane 66.51
    1-chlorotetradecane 30.49
    n-nonane 15.59
    undecane 12.69
    tert-butylcyclohexane 25.17
    cyclooctane 9.37
    cyclopentanol 204.56
    tetrahydropyran 342.08
    tert-amyl methyl ether 189.45
    2,5,8-trioxanonane 383.62
    1-hexene 92.14
    2-isopropoxyethanol 203.33
    2,2,2-trifluoroethanol 200.36
    methyl butyrate 335.21

    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