Addition von Aldehyden an aktivierte Doppelbindungen, XXXII. Synthesen und Reaktionen von 1,4‐Diketoketalen, 1,4,8‐Triketonen und 1,4,9‐Triketonen

Stetter, Hermann; Mertens, Alfred

doi:10.1002/cber.19811140714

Cited by 10 publications

(1 citation statement)

References 11 publications

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“…TLC of the crude product [petroleum ether/ethyl acetate (4:1), silica gel]: R f = 0.83, 0.63 (both weak), 0.37 ( 26 ). The fraction with R f = 0.37 was isolated by flash chromatography [petroleum ether/methyl tert ‐butyl ether (1:1 as eluent] and distilled in the kugelrohr oven at 150 °C/0.1 mbar to give 60 mg (75%) of 26 as a slightly yellow oil 14. For comparison this reaction was performed at reflux temperature (20 min.…”

Section: Methodsmentioning

confidence: 99%

A Putatively Unfeasible Heck Reaction − From Cyclopentenones to Annulated Ring Systems

Dyker¹,

Markwitz²,

Henkel³

2001

Eur. J. Org. Chem.

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Section: Methodsmentioning

confidence: 99%

A Putatively Unfeasible Heck Reaction − From Cyclopentenones to Annulated Ring Systems

Dyker¹,

Markwitz²,

Henkel³

2001

Eur. J. Org. Chem.

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The Catalyzed NucleophilicAddition of Aldehydes to Electrophilic Double Bonds

1991

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The cyanide‐ion‐catalyzed dimerization of aromatic and heterocyclic aldehydes to α‐hydroxy ketones, also known as the benzoin condensation, is one of the oldest reactions in organic chemistry. A key intermediate in this reversible reaction is a nitrile‐stabilized carbanion. In 1973 it was shown that these carbanions add irreversibly to α,β‐unsaturated ketones, esters, and nitriles to give 1,4‐diketones, 4‐ketocarboxylic esters, and 4‐ketocarbonitriles, respectively. The reaction succeeds only in aprotic solvents, preferably dimethylformamide. Benzoins and aldehydes can be used interchangeably as starting materials since they are in rapid equilibrium. Cyanide ion catalysis fails with aliphatic aldehydes because they resinify under the strongly basic conditions. Vitamin B 1 (thiamine) has long been known to convert aliphatic aldehydes into acyloins in buffered aqueous solution. The catalytic effect of vitamin B 1 is due to the presence of a thiazolium cation. Thiazolium salts in general as well as other azolium salts also catalyze the formation of acyloins. The optimum conditions for thiazolium salt catalysis have been worked out. It was shown subsequently that thiazolium salts, in combination with bases, also catalyze the addition of aliphatic, aromatic, and heterocyclic aldehydes to α,β‐unsaturated carbonyl compounds. The 1,4‐diketones, 4‐ketocarboxylic esters, and 4‐ketocarbonitriles are usually formed in good to excellent yields. Cyanide ion and thiazolium salt catalysis thus complement each other. This chapter covers the literature of the catalyzed nucleophilic addition of aldehydes to electrophilic double bonds up to 1988. The reaction has been reviewed previously.

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Addition von Aldehyden an aktivierte Doppelbindungen, XXXIII. Synthesen und Reaktionen von ether‐ und von estergruppenhaltigen γ‐Diketonen

Stetter

Leinen

1983

Chem. Ber.

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Durch Oxidation der entsprechenden Alkohole mit Pyridinium-chlorochromat werden die esteroder ethergruppenhaltigen Aldehyde 1 -8 erhalten. Die Thiazoliumsalz-katalysierten Additionen dieser Aldehyde an Vinylketone liefern die y-Diketone 9 -22. 2,3-O-Isopropylidenglycerinaldehyd addiert sich an Vinylketone unter Bildung der 1-(2,2-Dimethyl-l,3-dioxolan-4-yl)-1,4-diketone 23 -29. Einige Folgereaktionen der dargestellten y-Diketone werden beschrieben.Addition of Aldehydes to Activated Double Bonds, XXXIII Syntheses and Reactions of y-Diketones Containing Etheror Ester GroupsThe aldehydes 1 -8 containing ether-or ester groups are prepared by oxidation of the corresponding alcohols with pyridinium chlorochromate. Thiazolium salt-catalyzed additions of these aldehydes to vinyl ketones lead to y-diketones 9 -22. 2,3-O-Isopropylideneglyceraldehyde adds to vinyl ketones forming 1-(2,2-dimethyl-1,3-dioxolan-4-yl)-1,4-diketones 23 -29. Some reactions of the y-diketones are described.In fruheren Veroffentli~hungen~~~) beschrieben wir die Darstellung von ether-und estergruppenhaltigen 1,4-Diketonen durch Thiazoliumsalz-katalysierte Additionen von Aldehyden an Alkoxyvinylketone und an (Acetoxymethy1)vinylketone und von Alkoxyacetaldehyden an Vinylketone. Die vorliegende Arbeit befafit sich mit der Thiazoliumsalz-katalysierten Addition von 4-Alkoxy-butanalen, 5-Alkoxy-pentanalen, 4-Acetoxy-(bzw. 4-Benzoyloxy)-butanal und 5-Benzoyloxy-pentanal an Vinylketone. Die Aldehyde l -8 wurden durch Oxidation der betreffenden 4-Alkoxy-l-butanole, 5-Alkoxy-l-pentanole4) bzw. 4-Acet0xy-~) (bzw. 4-Benzoyloxy)-l-butanol und 5-Benzoyloxy-l-pentano16) mit Pyridinium-chlorochromat (PCC) ' ) hergestellt.Die Additionen der Aldehyde 1 -8 an die Vinylketone zu den 1,4-Diketonen 9 -22 wurden in absolutem Dioxan in Gegenwart von Triethylamin als Hilfsbase und 3-Benzyl-5-(2-hydroxyethyl)-4-methyl-l,3-thiazolium-chlorid (HEMBT + C1-) *) als Katalysator durchgefuhrt.Wahrend Ether-und Esteraldehyde dabei glatt reagieren, gelingt die Addition bei ungeschutzten Hydroxyaldehyden nur in seltenen Fallen9). Insbesondere gelang die Addition von Aldosen bisher nicht. Nunmehr konnte der durch Ketalisierung geschiitzte D-Glycerinaldehyd lo) an Vinylketone addiert werden. Unter Racemisierung werden die entsprechenden 1-(2,2-Dimethyl-l, 3-dioxolan-4-yl)-l ,Cdiketone 23 -29 erhalten. 0

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Addition von Aldehyden an aktivierte Doppelbindungen, XXXII. Synthesen und Reaktionen von 1,4‐Diketoketalen, 1,4,8‐Triketonen und 1,4,9‐Triketonen

Abstract: Die Vinylketone 4 -6 lassen sich durch Thiazoliumsalz-katalysierte Addition von Aldehyden zu 1,4-Diketoketalen 7 -13 und 1,4,8-Triketonen 14 -23 umsetzen.

Cited by 10 publications

References 11 publications

A Putatively Unfeasible Heck Reaction − From Cyclopentenones to Annulated Ring Systems

A Putatively Unfeasible Heck Reaction − From Cyclopentenones to Annulated Ring Systems

The Catalyzed NucleophilicAddition of Aldehydes to Electrophilic Double Bonds

Addition von Aldehyden an aktivierte Doppelbindungen, XXXIII. Synthesen und Reaktionen von ether‐ und von estergruppenhaltigen γ‐Diketonen

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