Glycol cleavage is a specific type of organic chemistry oxidation. The carbon–carbon bond in a vicinal diol (glycol) is cleaved and instead the two oxygen atoms become double-bonded to their respective carbon atoms. Depending on the substitution pattern in the diol, these carbonyls will be ketones and/or aldehydes.[1]
Glycol cleavage is an important for determining the structures of sugars. After cleavage of the glycol, the ketone and aldehyde fragments can be inspected and the location of the former hydroxyl groups ascertained.[2]
Reagents
Iodine-based reagents such as periodic acid (HIO4) and (diacetoxyiodo)benzene (PhI(OAc)2) are commonly used.[3] Another reagent is lead tetraacetate (Pb(OAc)4).[4] These I- and Pb-based methods are called the Malaprade reaction and Criegee oxidation, respectively. The former is favored for aqueous solutions, the latter for nonaqueous solutions.[1]
Cyclic intermediate are invariably invoked. The ring then fragments, with cleavage of the carbon–carbon bond and formation of carbonyl groups.
Warm concentrated potassium permanganate (KMnO4) will react with an alkene to form a glycol. Following this dihydroxylation, the KMnO4 can then cleave the glycol to give aldehydes or ketones. The aldehydes will react further with (KMnO4), being oxidized to become carboxylic acids. Controlling the temperature, concentration of the reagent and the pH of the solution can keep the reaction from continuing past the formation of the glycol.
References
- 1 2 Smith, Michael B.; March, Jerry (2007), Advanced Organic Chemistry: Reactions, Mechanisms, and Structure (6th ed.), New York: Wiley-Interscience, p. 1732-1733, ISBN 978-0-471-72091-1
- ↑ Wade LG. Organic Chemistry (6th ed.). Upper Saddle River, New Jersey, 2005: Prentice Hall. pp. 358–361, 489–490. ISBN 0-13-147882-6.
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- ↑ Christopher R. Schmid, Jerry D. Bryant (1995). "D-(R)-Glyceraldehyde Acetonide". Organic Syntheses. 72: 6. doi:10.15227/orgsyn.072.0006.
- ↑ Nicolaou KC, Adsool VA, Hale CR (April 2010). "An expedient procedure for the oxidative cleavage of olefinic bonds with PhI(OAc)2, NMO, and catalytic OsO4". Organic Letters. 12 (7): 1552–5. doi:10.1021/ol100290a. PMC 2848477. PMID 20192259.
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By consumption | Alcohols found in alcoholic drinks |
- 1-Propanol
- 2-Methyl-1-butanol
- Ethanol
- Isoamyl alcohol
- Isobutanol
- Phenethyl alcohol
- tert-Amyl alcohol
- tert-Butyl alcohol
- Tryptophol
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Medical alcohol |
- Ethchlorvynol
- Methylpentynol
- Methanol poisoning
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Toxic alcohols |
- Isopropyl alcohol
- Methanol
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Primary alcohols (1°) | Methanol |
- 4-Methylcyclohexanemethanol
- Aminomethanol
- Cyclohexylmethanol
- Methoxymethanol
- Methylazoxymethanol
- Trifluoromethanol
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Ethanol |
- 1-Aminoethanol
- 2,2,2-Trichloroethanol
- 2,2,2-Trifluoroethanol
- 2-(2-Ethoxyethoxy)ethanol
- 2-(2-Methoxyethoxy)ethanol
- 2-(2-Methoxyethoxy)ethanol
- 2-Butoxyethanol
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- 2-Methoxyethanol
- Aminoethylethanolamine
- Diethylethanolamine
- Dimethylethanolamine
- Ethanol
- Ethanolamine
- N,N-Diisopropylaminoethanol
- N-Methylethanolamine
- Phenoxyethanol
- Tribromoethanol
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Butanol |
- 2-Methyl-1-butanol
- Isobutanol
- n-Butanol
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Straight-chain saturated C1 — C9 |
- Methanol
- Ethanol
- 1-Propanol
- 1-Butanol
- 1-Pentanol
- 1-Hexanol
- 1-Heptanol
- 1-Octanol (capryl)
- 1-Nonanol (pelargonic)
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Straight-chain saturated C10 — C19 |
- 1-Decanol (capric)
- 1-Undecanol (hendecyl)
- 1-Dodecanol (lauryl)
- 1-Tridecanol
- 1-Tetradecanol (myristyl)
- 1-Pentadecanol
- 1-Hexadecanol (cetyl / palmityl)
- 1-Heptadecanol
- 1-Octadecanol (stearyl)
- 1-Nonadecanol
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Straight-chain saturated C20 — C29 |
- 1-Icosanol (arachidyl)
- 1-Heneicosanol
- 1-Docosanol (behenyl)
- 1-Tricosanol
- 1-Tetracosanol (lignoceryl)
- 1-Pentacosanol
- 1-Hexacosanol (ceryl)
- 1-Heptacosanol
- 1-Octacosanol (cluytyl / montanyl)
- 1-Nonacosanol
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Straight-chain saturated C30 — C39 |
- 1-Triacontanol (melissyl / myricyl)
- 1-Hentriacontanol
- 1-Dotriacontanol (lacceryl)
- 1-Tritriacontanol
- 1-Tetratriacontanol (geddyl)
- 1-Pentatriacontanol
- 1-Hexatriacontanol
- 1-Heptatriacontanol
- 1-Octatriacontanol
- 1-Nonatriacontanol
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Straight-chain saturated C40 — C49 |
- 1-Tetracontanol
- 1-Hentetracontanol
- 1-Dotetracontanol
- 1-Tritetracontanol
- 1-Tetratetracontanol
- 1-Pentatetracontanol
- 1-Hexatetracontanol
- 1-Heptatetracontanol
- 1-Octatetracontanol
- 1-Nonatetracontanol
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- 2-Ethylhexanol
- Allyl alcohol
- Anisyl alcohol
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Secondary alcohols (2°) |
- 1-Phenylethanol
- 2-Butanol
- 2-Deoxyerythritol
- 2-Heptanol
- 3-Heptanol
- 2-Hexanol
- 3-Hexanol
- 3-Methyl-2-butanol
- 2-Nonanol
- 2-Octanol
- 2-Pentanol
- 3-Pentanol
- Cyclohexanol
- Cyclopentanol
- Cyclopropanol
- Diphenylmethanol
- Isopropanol
- Pinacolyl alcohol
- Pirkle's alcohol
- Propylene glycol methyl ether
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Tertiary alcohols (3°) |
- 2-Methyl-2-pentanol
- 2-Methylheptan-2-ol
- 2-Methylhexan-2-ol
- 3-Methyl-3-pentanol
- 3-Methyloctan-3-ol
- Diacetone alcohol
- Ethchlorvynol
- Methylpentynol
- Nonafluoro-tert-butyl alcohol
- tert-Amyl alcohol
- tert-Butyl alcohol
- Triphenylethanol
- Triphenylmethanol
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Hydric alcohols | Monohydric alcohols |
- Methanol (C1)
- Ethanol (C2)
- Isopropanol (C3)
- 1-Butanol (C4)
- 1-Pentanol (C5)
- Cetyl alcohol (C16)
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Dihydric alcohols |
- Ethylene glycol
- Propylene glycol
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Trihydric alcohols | |
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Polyhydric alcohols (sugar alcohols) |
- Pentaerythritol
- Ethylene glycol (C2)
- Glycerol, Propylene glycol (C3)
- Erythritol, Threitol (C4)
- Xylitol (C5)
- Mannitol, Sorbitol (C6)
- Volemitol (C7)
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Amyl alcohols |
- 2,2-Dimethylpropan-1-ol
- 2-Methylbutan-1-ol
- 2-Methylbutan-2-ol
- 3-Methylbutan-1-ol
- 3-Methylbutan-2-ol
- Pentan-1-ol
- Pentan-2-ol
- Pentan-3-ol
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Aromatic alcohols |
- Benzyl alcohol
- 2,4-Dichlorobenzyl alcohol
- 3-Nitrobenzyl alcohol
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Saturated fatty alcohols |
- Cetostearyl alcohol
- Decanol
- Lauryl alcohol
- Myristyl alcohol
- Nonanol
- Octanol
- Tridecanol
- Undecanol
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Branched and unsaturated fatty alcohols |
- 3-Methyl-3-pentanol
- Erucyl alcohol
- Linolenyl alcohol
- Linoleyl alcohol
- Oleyl alcohol
- Palmitoleyl alcohol
- tert-Amyl alcohol
- tert-Butyl alcohol
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Sugar alcohols | C1 — C7 |
- Methylene glycol (C1)
- Ethylene glycol (C2)
- Glycerol (C3)
- Erythritol (C4)
- Threitol (C4)
- Arabitol (C5)
- Ribitol (C5)
- Xylitol (C5)
- Mannitol (C6)
- Sorbitol (C6)
- Galactitol (C6)
- Iditol (C6)
- Volemitol (C7)
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Deoxy sugar alcohols | |
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Cyclic sugar alcohols | |
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Glycylglycitols |
- Maltitol
- Lactitol
- Isomalt
- Maltotriitol
- Maltotetraitol
- Polyglycitol
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Terpene alcohols | Monoterpene alcohols |
- Borneol
- Citronellol
- Geraniol
- Linalool
- Menthol
- Nerol
- Rhodinol
- Terpineol
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Sesquiterpene alcohols |
- Bisabolol
- Farnesol
- Nerolidol
- Patchoulol
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Diterpene alcohols | |
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Dialcohols |
- 1,4-Butanediol
- 1,5-Pentanediol
- 2-Methyl-2-propyl-1,3-propanediol
- Diethylpropanediol
- Ethylene glycol
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Trialcohols | |
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Sterols |
- Cholesterol
- Ergosterol
- Lanosterol
- β-Sitosterol
- Stigmasterol
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Fluoroalcohols |
- 1,3-Difluoro-2-propanol
- 2,2,2-Trifluoroethanol
- 2-Fluoroethanol
- Nonafluoro-tert-butyl alcohol
- Trifluoromethanol
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Preparations | |
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Reactions | |
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