2(5H)-Furanone

Overview IFRA Botanical Request a quote

  • Identifiers

    CAS number
    497-23-4

    Molecular formula
    C4H4O2

    SMILES
    C1C=CC(=O)O1

    Safety labels

    Irritant
    Irritant

  • Odor profile

    Sweet 70.35%
    Caramellic 56.71%
    Coumarinic 55.47%
    Nutty 53.26%
    Coconut 49.03%
    Burnt 48.63%
    Buttery 45.12%
    Spicy 40.6%
    Tobacco 39.76%
    Winey 35.5%

    Scent© AI

  • Properties

    XLogP3-AA
    -0.6

    Molecular weight
    84.07 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Moderately fast

    Melting point expt.

    • 4-5 °C
    • 4.5 °C

    Boiling point

    • BP: 86-87 °C at 12 mm Hg
    • 86.00 to 87.00 °C. @ 12.00 mm Hg

    Flash point est.
    68.23 ˚C

    Flash point expt.

    • 101 °C (214 °F) (Closed cup)

    Solubility expt.

    • Soluble in water
    • Soluble (in ethanol)

  • Synonyms

    • 2(5H)-Furanone
    • 497-23-4
    • Furan-2(5H)-one
    • BUTENOLIDE
    • Isocrotonolactone
    • 2-Butenolide
    • 2-Buten-4-olide
    • 2H-furan-5-one
    • gamma-Crotonolactone
    • 2-Oxo-2,5-dihydrofuran
    • 4-Hydroxy-2-butenoic acid lactone
    • gamma-Crotolactone
    • Crotonolactone
    • alpha,beta-Crotonolactone
    • 2-(5H)-furanone
    • 2,5-dihydrofuran-2-one
    • delta,alpha,beta-Butenolide
    • gamma-Hydroxycrotonic acid lactone
    • 2-Butenoic acid gamma-lactone
    • 2-Butenoic acid-gamma-lactone
    • 5H-furan-2-one
    • 2,5-Dihydrofuranone
    • but-2-en-4-olide
    • 4-Hydroxycrotonic acid gamma-lactone
    • .gamma.-Crotonolactone
    • CCRIS 5722
    • 2-Buten-1,4-olide
    • NSC 197009
    • 2-Butenoic acid, 4-hydroxy-, gamma-lactone
    • EINECS 207-839-3
    • MFCD00005376
    • UNII-8KXK25H388
    • BRN 0383585
    • CRATONE
    • 4-Hydroxy-2-butenoic acid gamma-lactone
    • HSDB 8151
    • 8KXK25H388
    • .delta.,.alpha.,.beta.-Butenolide
    • NSC-197009
    • .BETA.-CROTONOLACTONE
    • CHEMBL166223
    • Crotonic acid, 4-hydroxy-, .gamma.-lactone
    • DTXSID7075422
    • FEMA NO. 4138
    • CHEBI:38118
    • 2-Butenoic acid-.gamma.-lactone
    • 2-Butenoic acid, 4-hydroxy-, .gamma.-lactone
    • 5-17-09-00112 (Beilstein Handbook Reference)
    • .gamma.-Hydroxycrotonic acid lactone
    • Crotonic acid, 4-hydroxy-, gamma-lactone (6CI,7CI)
    • Crotonic acid, 4-hydroxy-, gamma-lactone
    • 4-Hydroxy-2-butenoic acid .gamma.-lactone
    • 5-OXO-2,5-DIHYDROFURAN-3-YL ESTER
    • 4-HYDROXY-2-BUTENOIC ACID .GAMMA.-LACTONE [FHFI]
    • .DELTA..alpha.,.beta.-Butolide
    • 2-Butenoic acid, .gamma.-lactone
    • .DELTA..alpha.,.beta.-Butenolide
    • ?-Crotonolactone
    • 5H-furanone
    • 2_5H_furanone
    • .gamma.-Crotolactone
    • 5 H-Furan-2-one
    • (5H)-furan-2-one
    • alpha, beta-Crotolactone
    • alpha,alpha,beta-Butolide
    • BETA-CROTONOLACTONE
    • 2(5H)FURANONE
    • 2(5H)-Furanone, 98%
    • delta, alpha, beta-Butenolide
    • laquo gammaRaquo -crotolactone
    • .alpha.,.beta.-Crotonolactone
    • laquo gammaRaquo -crotonolactone
    • DTXCID9040718
    • VIHAEDVKXSOUAT-UHFFFAOYSA-
    • BCP15247
    • NSC51296
    • BBL103594
    • BDBM50360798
    • NSC-51296
    • NSC197009
    • STL557404
    • AKOS000268618
    • CS-W008270
    • FF45970
    • HY-W008270
    • laquo deltaRaquo ,alpha,beta-butenolide
    • SB60895
    • gamma-Crotonolactone;2-Buten-1,4-olide
    • SY017893
    • 2-Butenoic acid-laquo gammaRaquo -lactone
    • DB-027466
    • 2-Oxo-2,5-dihydrofuran(2-[5H]-furanone)
    • NS00021175
    • EN300-80159
    • laquo gammaRaquo -hydroxycrotonic acid lactone
    • C17601
    • 2(5H)-Furanone (laquo gammaRaquo -crotonolactone)
    • 4-Hydroxy-2-butenoic acid laquo gammaRaquo -lactone
    • Q4596886
    • Crotonic acid, 4-hydroxy-, laquo gammaRaquo -lactone
    • 2-Butenoic acid, 4-hydroxy-, laquo gammaRaquo -lactone
    • Z1219048777
    • InChI=1/C4H4O2/c5-4-2-1-3-6-4/h1-2H,3H2
    • 207-839-3

  • Applications

    2(5H)-Furanone (CAS 497-23-4), also known as butenolide, is a versatile unsaturated lactone used primarily as a building block in organic synthesis: a Michael acceptor and dienophile for backbone editing, a precursor for ring-opening/saturation to access gamma- and delta-lactones, succinate and maleate derivatives; an intermediate toward pharmaceuticals and natural products bearing the butenolide motif (e.g., prostaglandin/butenolide families and halogenated furanone quorum-sensing inhibitors), a platform in agrochemical and insect-pheromone synthesis, and a feedstock for constructing aroma lactones in flavor and fragrance chemistry; it is also explored in materials science as a comonomer or surface-functionalization unit, a precursor to biodegradable polyesters via ring-opening pathways, and as an analytical reference—typically employed at lab-to-fine-chemical scale as a flexible synthon rather than a direct end-use ingredient.

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 369.61
    methanol 723.36
    isopropanol 230.87
    water 196.99
    ethyl acetate 94.94
    n-propanol 209.0
    acetone 216.14
    n-butanol 187.83
    acetonitrile 287.4
    DMF 444.54
    toluene 38.07
    isobutanol 166.76
    1,4-dioxane 167.8
    methyl acetate 161.12
    THF 148.41
    2-butanone 154.96
    n-pentanol 165.96
    sec-butanol 195.81
    n-hexane 9.94
    ethylene glycol 191.91
    NMP 371.84
    cyclohexane 6.65
    DMSO 418.1
    n-butyl acetate 63.36
    n-octanol 91.03
    chloroform 177.72
    n-propyl acetate 86.75
    acetic acid 651.91
    dichloromethane 259.51
    cyclohexanone 125.99
    propylene glycol 156.07
    isopropyl acetate 57.0
    DMAc 432.67
    2-ethoxyethanol 319.2
    isopentanol 185.55
    n-heptane 7.21
    ethyl formate 128.03
    1,2-dichloroethane 127.71
    n-hexanol 85.38
    2-methoxyethanol 387.5
    isobutyl acetate 50.91
    tetrachloromethane 26.75
    n-pentyl acetate 58.1
    transcutol 783.57
    n-heptanol 61.22
    ethylbenzene 36.2
    MIBK 77.24
    2-propoxyethanol 167.05
    tert-butanol 263.42
    MTBE 127.16
    2-butoxyethanol 135.25
    propionic acid 234.45
    o-xylene 42.51
    formic acid 599.9
    diethyl ether 87.12
    m-xylene 34.73
    p-xylene 50.1
    chlorobenzene 64.7
    dimethyl carbonate 70.48
    n-octane 4.49
    formamide 693.89
    cyclopentanone 158.48
    2-pentanone 100.19
    anisole 124.76
    cyclopentyl methyl ether 72.2
    gamma-butyrolactone 215.52
    1-methoxy-2-propanol 240.42
    pyridine 183.26
    3-pentanone 69.87
    furfural 302.14
    n-dodecane 5.49
    diethylene glycol 201.25
    diisopropyl ether 28.11
    tert-amyl alcohol 246.3
    acetylacetone 110.2
    n-hexadecane 5.62
    acetophenone 135.0
    methyl propionate 92.9
    isopentyl acetate 61.97
    trichloroethylene 236.9
    n-nonanol 74.56
    cyclohexanol 103.64
    benzyl alcohol 145.45
    2-ethylhexanol 56.11
    isooctanol 56.71
    dipropyl ether 38.77
    1,2-dichlorobenzene 74.35
    ethyl lactate 76.37
    propylene carbonate 122.92
    n-methylformamide 347.39
    2-pentanol 121.15
    n-pentane 10.68
    1-propoxy-2-propanol 111.77
    1-methoxy-2-propyl acetate 72.3
    2-(2-methoxypropoxy) propanol 172.53
    mesitylene 24.32
    ε-caprolactone 132.67
    p-cymene 25.6
    epichlorohydrin 217.82
    1,1,1-trichloroethane 68.75
    2-aminoethanol 277.29
    morpholine-4-carbaldehyde 364.48
    sulfolane 239.98
    2,2,4-trimethylpentane 10.76
    2-methyltetrahydrofuran 133.39
    n-hexyl acetate 98.09
    isooctane 6.87
    2-(2-butoxyethoxy)ethanol 232.11
    sec-butyl acetate 55.62
    tert-butyl acetate 64.04
    decalin 8.65
    glycerin 238.06
    diglyme 346.58
    acrylic acid 290.41
    isopropyl myristate 38.04
    n-butyric acid 185.07
    acetyl acetate 69.9
    di(2-ethylhexyl) phthalate 56.07
    ethyl propionate 70.04
    nitromethane 609.09
    1,2-diethoxyethane 124.77
    benzonitrile 133.41
    trioctyl phosphate 35.64
    1-bromopropane 64.37
    gamma-valerolactone 256.74
    n-decanol 55.81
    triethyl phosphate 38.48
    4-methyl-2-pentanol 81.9
    propionitrile 146.13
    vinylene carbonate 147.57
    1,1,2-trichlorotrifluoroethane 231.72
    DMS 81.46
    cumene 33.09
    2-octanol 50.44
    2-hexanone 97.98
    octyl acetate 53.13
    limonene 32.15
    1,2-dimethoxyethane 297.56
    ethyl orthosilicate 36.51
    tributyl phosphate 45.37
    diacetone alcohol 131.64
    N,N-dimethylaniline 106.34
    acrylonitrile 223.21
    aniline 103.76
    1,3-propanediol 262.96
    bromobenzene 51.45
    dibromomethane 135.56
    1,1,2,2-tetrachloroethane 154.03
    2-methyl-cyclohexyl acetate 56.5
    tetrabutyl urea 66.21
    diisobutyl methanol 37.08
    2-phenylethanol 88.17
    styrene 48.88
    dioctyl adipate 62.62
    dimethyl sulfate 123.7
    ethyl butyrate 59.15
    methyl lactate 98.02
    butyl lactate 72.15
    diethyl carbonate 49.05
    propanediol butyl ether 194.06
    triethyl orthoformate 46.22
    p-tert-butyltoluene 22.75
    methyl 4-tert-butylbenzoate 109.13
    morpholine 210.31
    tert-butylamine 160.39
    n-dodecanol 42.37
    dimethoxymethane 171.8
    ethylene carbonate 95.9
    cyrene 148.75
    2-ethoxyethyl acetate 91.61
    2-ethylhexyl acetate 46.93
    1,2,4-trichlorobenzene 94.76
    4-methylpyridine 176.96
    dibutyl ether 58.86
    2,6-dimethyl-4-heptanol 37.08
    DEF 178.04
    dimethyl isosorbide 170.61
    tetrachloroethylene 121.69
    eugenol 138.9
    triacetin 118.33
    span 80 126.68
    1,4-butanediol 170.07
    1,1-dichloroethane 98.38
    2-methyl-1-pentanol 175.65
    methyl formate 237.08
    2-methyl-1-butanol 180.4
    n-decane 7.96
    butyronitrile 133.06
    3,7-dimethyl-1-octanol 86.86
    1-chlorooctane 31.61
    1-chlorotetradecane 13.95
    n-nonane 7.43
    undecane 6.44
    tert-butylcyclohexane 9.73
    cyclooctane 3.19
    cyclopentanol 109.23
    tetrahydropyran 94.0
    tert-amyl methyl ether 104.14
    2,5,8-trioxanonane 260.7
    1-hexene 39.25
    2-isopropoxyethanol 198.64
    2,2,2-trifluoroethanol 236.69
    methyl butyrate 105.87

    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

Botanical

Name CAS Botanical Proportion
Saffron 1 8022-19-3 Crocus sativus L., fam. Iridaceae 0.1%