Jones oxidation: Difference between revisions - Wikipedia

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{{Short description|Oxidation of alcohol}}

{{Reactionbox

| Name = Jones oxidation

| Type = Organic redox reaction

| NamedAfter = [[Ewart Jones]]

| Section3 = {{Reactionbox Identifiers

| OrganicChemistryNamed = jones-oxidation

| RSC_ontology_id = 0000356

}}▼

}}

▲ }}

The '''Jones oxidation''' is an [[organic reaction]] for the [[redox|oxidation]] of primary and secondary [[alcohol]]s to [[carboxylic acid]]s and [[ketone]]s, respectively. It is named after its discoverer, [[Ewart Jones|Sir Ewart Jones]].<ref name="Bowden 1946">{{cite journal|author1=Bowden, K. |author2=Heilbron, I. M. |author3=Jones, E. R. H |journal = [[J. Chem. Soc.]]|year = 1946|pages = 39|doi = 10.1039/jr9460000039|title = 13. Researches on acetylenic compounds. Part I. The preparation of acetylenic ketones by oxidation of acetylenic carbinols and glycols}}</ref>▼

The '''Jones oxidation''' is an [[organic reaction]] for the [[redox|oxidation]] of primary and secondary [[alcohol (chemistry)|alcohol]]s to [[carboxylic acid]]s and [[ketone]]s, respectively. It is named after its discoverer, [[Ewart Jones|Sir Ewart Jones]]. The reaction was an early method for the oxidation of alcohols. Its use has subsided because milder, more selective reagents have been developed, e.g. [[Collins reagent]].<ref>{{cite book |doi=10.1007/0-387-25725-X_1|chapter=Chromium-based Reagents|title=Oxidation of Alcohols to Aldehydes and Ketones|series=Basic Reactions in Organic Synthesis|year=2006|pages=1–95|isbn=0-387-23607-4}}</ref>

[[File:Jones Oxidation Scheme.png|center|300px|The Jones oxidation]]

'''Jones reagent''' is a solution ofprepared by dissolving [[chromium trioxide]] in diluteaqueous [[sulfuric acid]] and acetone. A mixtureTo ofeffect potassiuma dichromateJones andoxidation, dilutethis sulfuricacidic acidmixture canis alsothen beadded used. Theto solventan [[acetone]] markedlysolution affectsof the propertiessubstrate. ofAlternatively, the[[potassium chromicdichromate]] acidcan be used in place of chromium trioxide. The oxidation is very rapid, and quite [[exothermic]],. and the yieldsYields are typically high. The reagent rarelyis oxidizesconvenient and cheap. However, Cr(VI) compounds are carcinogenic, which deters the use of unsaturatedthis bondsmethodology.

==Stoichiometry and mechanism==▼

▲==Stoichiometry==

Jones reagent will convert primary and secondary alcohols to aldehydes and ketones, respectively. Depending on the reaction conditions, the aldehydes may then be converted to carboxylic acids. For oxidations to the aldehydes and ketones, two equivalents of chromic acid oxidize three equivalents of the alcohol:

: 2 HCrO₄⁻ + 3 RR'C(OH)H + 8 H⁺ + 4 H₂O → 2 [Cr(H₂O)₆]³⁺ + 3 RR'CO

For oxidation of primary alcohols to carboxylic acids, one4 equivalentequivalents of Joneschromic reagentacid isoxidize required3 forequivalents eachof the substratealcohol. The aldehyde is an intermediate.

:4 HCrO₄⁻ + 3 RCH₂OH + 16 H⁺ + 11 H₂O → 4 [Cr(H₂O)₆]³⁺ + 3 RCOOH

The inorganic products are green, characteristic of [[metal aquo complex|chromium(III) aquo complexes]].<ref name=cyclooct/>

Like many other oxidations of alcohols by metal oxides, the reaction proceeds via the formation of a mixed [[chromate ester]]:<ref name=March>{{March6th}}</ref><ref>{{cite book|author1=Ley, S. V. |author2=Madin, A. |title = Comprehensive organic synthesis|year = 1991|volume=7|pages = 253–256 |editor1=B. M. Trost |editor2=I. Fleming |publisher=Pergamon Press|place=Oxford}}</ref> These esters[[ester]]s have the formula CrO₃(OCH₂R)⁻▼

==Mechanism==

▲Like many other oxidations of alcohols by metal oxides, the reaction proceeds via the formation of a mixed [[ester]]:<ref name=March>{{March6th}}</ref><ref>{{cite book|author1=Ley, S. V. |author2=Madin, A. |title = Comprehensive organic synthesis|year = 1991|volume=7|pages = 253–256 |editor1=B. M. Trost |editor2=I. Fleming |publisher=Pergamon Press|place=Oxford}}</ref> These esters have the formula CrO₃(OCH₂R)⁻

:CrO₃(OH)⁻ + RCH₂OH → CrO₃(OCH₂R)⁻ + H₂O

Like conventional esters, the formation of this [[chromate ester]] is accelerated by the acid. These esters can be isolated when the alcohol lacksis tertiary because these lack the [[alpha and beta carbon|α-C-H]] hydrogen that would be lost to form the bondscarbonyl. For example, using [[tert-Butyl alcohol|''tert''-butyl alcohol]], one can isolate [[Tert-Butyl chromate|''tert''-butyl chromate]] ((CH₃)₃CO)₂CrO₂), (which is itself a good oxidant).<ref>Fillmore Freeman, "Di-tert-butyl Chromate" Encyclopedia of Reagents for Organic Synthesis, 2001, John Wiley & Sons, Ltd. {{DOIdoi|10.1002/047084289X.rd059m}}</ref>

For Thethose structures with hydrogen alpha to the oxygen, the chromate esters degrade, releasing the carbonyl product and an ill-defined Cr(IV) product:

:CrO₃(OCH₂R)⁻ → "CrO₂OH⁻" + O=CHR

The partially deuterated alcohols HOCD₂R oxidize about six times slower than the undeuterated derivatives. This large [[kinetic isotope effect]] shows that the C–H (or C-DC–D) bond breaks in the [[rate-determining step]].

The reaction stoichiometry implicates the Cr(IV) species "CrO₂OH⁻", which [[comproportionation|comproportionates]] with the chromic acid to give a Cr(V) oxide, which also functions as an oxidant for the alcohol.<ref>Oxidation in Organic Chemistry. Edited by K. B. Wiberg, Academic Press, NY, 1965.</ref>

The oxidation of the aldehydes is proposed to proceed via the formation of [[hemiacetal]]-like intermediates, which arise from the addition of the O₃CrO-H⁻ bond across the C=O bond.

The reagent rarely oxidizes unsaturated bonds. In certain cases, depending on very

exact stereoelectronic factors, production of epoxides may occur.

==Illustrative reactions and applications==

Although useful reagent for some applications, due to the carcinogenic nature of chromium(VI), the Jones oxidation has slowly been replaced by other oxidation methods. It remains useful in [[organic synthesis]].<ref name=cyclooct>{{OrgSynth|collvol volume= 545|collvolpagespages = 31028|year = 19731965|title = Cyclooctanone|author first1= E. J.|last1= Eisenbraun|prep doi= cv5p031010.15227/orgsyn.045.0028}}</ref><ref>{{OrgSynth|collvol volume= 545|collvolpages page= 86677|year = 19731965|title = Nortricyclanone|author first1=J. |last1=Meinwald, |first2=J. |last2=Crandall, and |first3=W. E. |last3=Hymans|prep doi= cv5p086610.15227/orgsyn.045.0077}}</ref> A variety of spectroscopic techniques, including [[Infrared spectroscopy|IR]], can be used to monitor the progress of a Jones Oxidationoxidation reaction and confirm the presence of the oxidized product. At one time the Jones oxidation was used in primitive [[breathalyzer]]s.<ref name=breathalyzer>{{cite web|last=Freudenrich|first=Craig|title=How Breathalyzers Work|url=http://electronics.howstuffworks.com/gadgets/automotive/breathalyzer3.htm|work=How Stuff Works|accessdate=April 2011}}</ref> Aminoindans, which are of pharmalogical interest, are prepared by the oxidation of the alcohol to ketone which is converted into an amino group. The alcohol is oxidized to the ketone with the Jones reagent. The reagent was once used to prepare [[salicylic acid]], a precursor to aspirin.<ref>[http://www.mnstate.edu/jasperse/Chem365/Alcohol%20Aspirin.doc.pdf Alcohol Unknown (NMR)/Synthesis of Aspirin]</ref> Methcathinone is a psychoactive stimulant that is sometimes used as an addictive recreational [[drug]]. It can be oxidized from certain alcohols using the Jones reagent.<ref>{{cite journal|doi=10.1021/jm00270a004|author1=Solomons, E. |author2=Sam, J. |journal=Journal of Medicinal Chemistry|year=1973|volume=16|pages=1330–1333|title=2-Aminoindans of pharmacological interest|issue=12|pmid=4765859}}</ref>

==Related processes==

{{main|Oxidation with chromium(VI) complexes}}

Several other chromium compounds are used for the oxidation of alcohols.<ref name=March/> These include [[Collins reagent]] and [[pyridinium chlorochromate]]

The principal reagents are Collins reagent, PDC, and PCC. These reagents represent improvements over inorganic chromium(VI) reagents such as Jones reagent.

The [[Sarett oxidation]] is a similar process.

==Historical references==▼

▲The '''Jones oxidation''' is an [[organic reaction]] for the [[redox|oxidation]] of primary and secondary [[alcohol]]s to [[carboxylic acid]]s and [[ketone]]s, respectively. It is named after its discoverer, [[Ewart Jones|Sir Ewart Jones]].<ref name="Bowden 1946">*{{cite journal|author1=Bowden, K. |author2=Heilbron, I. M. |author3=Jones, E. R. H |journal = [[J. Chem. Soc.]]|year = 1946|pages = 39|doi = 10.1039/jr9460000039|title = 13. Researches on acetylenic compounds. Part I. The preparation of acetylenic ketones by oxidation of acetylenic carbinols and glycols}}</ref>

*{{cite journal|author1=Heilbron, I.M. |author2=Jones, E.R.H. |author3=Sondheimer, F |journal = [[J. Chem. Soc.]]|year = 1949|pages = 604|doi = 10.1039/jr9490000604|title = 129. Researches on acetylenic compounds. Part XV. The oxidation of primary acetylenic carbinols and glycols}}▼

*{{cite journal|author = Bladon, P|journal = [[J. Chem. Soc.]]|year = 1951|pages = 2402|doi = 10.1039/jr9510002402|title = 532. Studies in the sterol group. Part LII. Infra-red absorption of nuclear tri- and tetra-substituted ethylenic centres|last2 = Fabian|first2 = Joyce M.|last3 = Henbest|first3 = H. B.|last4 = Koch|first4 = H. P.|last5 = Wood|first5 = Geoffrey W.}}▼

*{{cite journal|author = Jones, E. R. H|journal = [[J. Chem. Soc.]]|year = 1953|pages = 457|doi = 10.1039/jr9530000457|title = 92. The chemistry of the triterpenes. Part XIII. The further characterisation of polyporenic acid A}}▼

*{{cite journal|author = Jones, E. R. H|journal = [[J. Chem. Soc.]]|year = 1953|pages = 2548|doi = 10.1039/jr9530002548|title = 520. The chemistry of the triterpenes and related compounds. Part XVIII. Elucidation of the structure of polyporenic acid C}}▼

*{{cite journal|author = Jones, E. R. H|journal = [[J. Chem. Soc.]]|year = 1953|pages = 3019|doi = 10.1039/jr9530003019|title = 599. The chemistry of the triterpenes and related compounds. Part XIX. Further evidence concerning the structure of polyporenic acid A}}▼

*{{cite journal|author = [[C. Djerassi]], R. Engle and A. Bowers|title = Notes – The Direct Conversion of Steroidal &#916;5Δ5-3&#946;3β-Alcohols to &#916;5Δ5- and &#916;4Δ4-3-Ketones|year = 1956|journal = [[J. Org. Chem.]]|volume = 21|issue = 12|pages = 1547–1549|doi = 10.1021/jo01118a627}}▼

==References==

{{reflist}}

[[Category:Organic redoxoxidation reactions]]▼

▲==Historical references==

▲*{{cite journal|author1=Heilbron, I.M. |author2=Jones, E.R.H. |author3=Sondheimer, F |journal = [[J. Chem. Soc.]]|year = 1949|pages = 604|doi = 10.1039/jr9490000604|title = 129. Researches on acetylenic compounds. Part XV. The oxidation of primary acetylenic carbinols and glycols}}

▲*{{cite journal|author = Bladon, P|journal = [[J. Chem. Soc.]]|year = 1951|pages = 2402|doi = 10.1039/jr9510002402|title = 532. Studies in the sterol group. Part LII. Infra-red absorption of nuclear tri- and tetra-substituted ethylenic centres|last2 = Fabian|first2 = Joyce M.|last3 = Henbest|first3 = H. B.|last4 = Koch|first4 = H. P.|last5 = Wood|first5 = Geoffrey W.}}

▲*{{cite journal|author = Jones, E. R. H|journal = [[J. Chem. Soc.]]|year = 1953|pages = 457|doi = 10.1039/jr9530000457|title = 92. The chemistry of the triterpenes. Part XIII. The further characterisation of polyporenic acid A}}

▲*{{cite journal|author = Jones, E. R. H|journal = [[J. Chem. Soc.]]|year = 1953|pages = 2548|doi = 10.1039/jr9530002548|title = 520. The chemistry of the triterpenes and related compounds. Part XVIII. Elucidation of the structure of polyporenic acid C}}

▲*{{cite journal|author = Jones, E. R. H|journal = [[J. Chem. Soc.]]|year = 1953|pages = 3019|doi = 10.1039/jr9530003019|title = 599. The chemistry of the triterpenes and related compounds. Part XIX. Further evidence concerning the structure of polyporenic acid A}}

▲*{{cite journal|author = [[C. Djerassi]], R. Engle and A. Bowers|title = Notes – The Direct Conversion of Steroidal &#916;5-3&#946;-Alcohols to &#916;5- and &#916;4-3-Ketones|year = 1956|journal = [[J. Org. Chem.]]|volume = 21|issue = 12|pages = 1547–1549|doi = 10.1021/jo01118a627}}

▲[[Category:Organic redox reactions]]

[[Category:Name reactions]]