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3- cyclobutanone

Among these ketones the thermal decomposition of methyl cyclobutyl ketone, cyclobutanone and cyclopentanone will be dealt with. In principle, they may decompose unimolecularly like the cycloalkanes or may split into free radicals as do the simple alkyl ketones. [Pg.271]

The reaction was studied by Daignault and Walters in the temperature range 360-410 °C. By infrared analysis ethylene and methyl vinyl ketone were shown to be formed in equal amounts. Mass-spectrometric analysis of the gas fraction revealed the presence of 99.4% C2H4, 0.1 % CjHe, 0.1 % C3H6, 0.03% CjHg and higher paraffins, 0.2 % butenes and 0.2 % of other C4 hydrocarbons. The stoichiometry of the decomposition can be given, almost quantitatively, by [Pg.271]

At least 99 % of the decomposition is homogeneous and the rate is not significantly affected by NO, propene or toluene. The reaction is first order between 10 and 65 torr pressure. The rate coefficient can be expressed (in the range 360-410 °C) as [Pg.271]

The kinetics of the decomposition has been studied by Das et al. between 333 and 373 °C. Infrared analysis revealed the presence of ketene and ethylene among the products. The gas fraction contained (after the removal of ketene) 99.4 % C2H4,0.5% cyclopropane and 0.1 % CO2. Accordingly, the stoichiometry of the decomposition is [Pg.271]

The pressure increase approaches 100 % at 368 °C and 5-10 torr initial pressure, but is less at higher pressures (probably due to the secondary reactions of the ketene formed). Surface effects are not significant, although the secondary reactions of the products are, to some extent, heterogeneous. [Pg.272]


Some other methods to synthesize 1,4-dicarbonyI compounds via cyclopropane or cyclobutanone derivatives are given in sections 1.13.1 and 1.13.2. [Pg.70]

If a bromomethyl- or vinyl-substituted cyclopropane carbon atom bears a hydroxy group, the homoallyiic rearrangement leads preferentially to cyclobutanone derivatives (J. Sa-laun, 1974). Addition of amines to cydopropanone (N. J. Turro, 1966) yields S-lactams after successive treatment with tert-butyl hypochlorite and silver(I) salts (H.H. Wasserman, 1975). For intramolecular cyclopropane formation see section 1.16. [Pg.77]

In the presence of a double bond at a suitable position, the CO insertion is followed by alkene insertion. In the intramolecular reaction of 552, different products, 553 and 554, are obtained by the use of diflerent catalytic spe-cies[408,409]. Pd(dba)2 in the absence of Ph,P affords 554. PdCl2(Ph3P)3 affords the spiro p-keto ester 553. The carbonylation of o-methallylbenzyl chloride (555) produced the benzoannulated enol lactone 556 by CO, alkene. and CO insertions. In addition, the cyclobutanone derivative 558 was obtained as a byproduct via the cycloaddition of the ketene intermediate 557[4I0]. Another type of intramolecular enone formation is used for the formation of the heterocyclic compounds 559[4l I]. The carbonylation of the I-iodo-1,4-diene 560 produces the cyclopentenone 561 by CO. alkene. and CO insertions[409,4l2]. [Pg.204]

Vinyl etheis cyclize with ketenes to cyclobutanones (239). [Pg.115]

Cyclobutanone [1191-95-3] M 70.1, b 96-97 , d 0.931, n 1.4189. Treated with dilute aqueous KMn04, dried with molecular sieves and fractionally distd. Purified via the semicarbazone, then regenerated, dried with CaS04, and distd in a spinning-band column. Alternatively, purified by preparative gas chromatography using a Carbowax 20-M column at 80°. (This treatment removes acetone). [Pg.176]

C. Cyclobutanone (Note 16). The residue consisting of oxaspiro-pentane (35%) and dichloromethane (about 200 ml.) is added dropwise at room temperature to a magnetically stirred solution containing about 5-10 mg. of lithium iodide in 50 ml. of dichloromethane (Notes 17, 18), at such a rate as to maintain gentle reflux of the solvent. At the end of the addition when the reaction mixture returns to room temperature, the transformation into cyclobutanone is complete. The dichloromethane solution is washed with 20 ml. of saturated aqueous sodium thiosulfate and with 20 ml. of water. After drying over magnesium sulfate and concentration by distillation of the solvent through a 15-cm., helix-packed, vacuum-insulated column, the residual liquid consists of cyclobutanone (95%) and of 3-buten-2-one and 2-methylpropenal... [Pg.37]

A final distillation at 760 mm. through a 50-cm. stainless-steel spinning band column yields 41 g. (64% from methylenecyclopropane) of pure cyclobutanone (b.p. 100-101°) (Notes 19, 20). [Pg.38]

If the oil bath temperature reaches 80°, the residue consists of cyclobutanone (75%) and oxaspiropentane (25%). Distillation of this residue at 97-103° (760 mm.) yields cyclobutanone and oxaspiropentane. [Pg.39]

The purity of cyclobutanone was checked by gas chromatography on a 3.6-m. column containing 20% silicone SE 30 on chromosorb W at 65°. The infrared spectrum (neat) shows carbonyl absorption at 1779 cm. - the proton magnetic resonance spectrum (carbon tetrachloride) shows a multiplet at 8 2.00 and a triplet at S 3.05 in the ratio 1 2. [Pg.39]

The cheekers obtained yields of 61-64% on smaller-scale runs ( 10 g. of cyclobutanone). [Pg.39]

This method for the preparation of cyclobutanone via oxaspiropentane is an adaptation of that described by Salaiin and Conia. The previously known large-scale preparations of cyclobutanone consist of the reaction of the hazardous diazomethane with ketene, the oxidative degradation or the ozonization in presence of pjrridine of methylenecyclobutane prepared from pentaerythritol, or the recently reported dithiane method of Corey and Seebach, which has the disadvantage of producing an aqueous solution of the highly water-soluble cyclobutanone. A procedure involving the solvolytic cyclization of 3-butyn-l-yl trifluoro-methanesulfonate is described in Org. Syn., 54, 84 (1974). [Pg.40]

The procedure described here is a large-scale preparation with satisfactory yields of a still very expensive but simple compound from very cheap and readily available starting materials and with ordinary laboratory equipment. This rearrangement of oxaspiropentanes into cyclobutanones appears to be general for the preparation of substituted cyclobutanones. ... [Pg.40]

This equation implies that the relative reactivity is independent of the specific nucleophile and that relative reactivity is insensitive to changes in position of the transition state. Table 8.4 lists the B values for some representative ketones. The parameter B indicates relative reactivity on a log scale. Cyclohexanone is seen to be a particularly reactive ketone, being almost as reactive as cyclobutanone and more than 10 times as reactive as acetone. [Pg.472]

When an aryl substituent is placed at C-5 of a 4-substituted cyclohexenone, a new product type containing a cyclobutanone ring is formed. [Pg.786]

The reaction products are the same for both direct irradiation and acetophenone sensitization. When the reactant B is used in homochiral form, the product D is nearly racemic (6% e.e.). Relate the formation of the cyclobutanones to the more normal products of type E and E Why does the 5-aryl substituent favor formation of the cyclobutanones Give a complete mechanism for formation of D which is consistent with the stereochemical result. [Pg.786]

The photochemistry of cyclobutanones differs from that of less strained larger cycloalkanones. Fragmentation to ethylene and ketene (derivatives), decarbonylation and rearrangement to oxacarbenes predominate here. The oxacarbene formation, which occurs with retention of the configuration of the... [Pg.293]

Photochemical transformations of conjugated cyclohexenones, 317 Photochemical transformations of non-conjugatea ketones, 292 Photochemistry of cyclobutanones, 293 Photolysis of nitrites, 253... [Pg.463]

There is some spectral evidence that acylation of enamines of cyclic ketones with acid chlorides having an a-hydrogen in the presence of triethylamine proceeds via the ketene and subsequent cycloaddition (84). The intermediate cyclobutanone is then opened to give the enamino ketone which is hydrolyzed to the 2-acyl cyclohexanone. In the case of enamines of larger cyclic ketones the alternate mode of the cyclobutanone opening predominates, with the formation of ring-expanded 1,3-diketones upon... [Pg.139]

The reaction between an aldehydic enamine with no (3 hydrogens and ketene yields a cyclobutanone adduct which is not thermally stable (Rj and R4 H, Ri = R2 = H) (67,70,72). Thermal decomposition gives just one... [Pg.226]


See other pages where 3- cyclobutanone is mentioned: [Pg.194]    [Pg.140]    [Pg.162]    [Pg.77]    [Pg.79]    [Pg.286]    [Pg.302]    [Pg.401]    [Pg.469]    [Pg.270]    [Pg.270]    [Pg.500]    [Pg.159]    [Pg.412]    [Pg.38]    [Pg.103]    [Pg.186]    [Pg.36]    [Pg.37]    [Pg.39]    [Pg.128]    [Pg.471]    [Pg.471]    [Pg.472]    [Pg.307]    [Pg.135]    [Pg.137]    [Pg.140]   
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1,3-Butadiene, 1-alkoxysilylsynthesis via cyclobutanones

2- cyclobutanone alkene

2- cyclobutanones, photolysis

2- cyclopentanone cyclobutanone

2- cyclopentanone cyclobutanone Transformation

3.3- dimethyl-cyclobutanones

ACS Symposium Series American Chemical Society: Washington cyclobutanone oxime

Alkyl-substituted cyclobutanones

Ammonium cyclobutanone

Annulation cyclobutanones

Baeyer cyclobutanone

Baeyer-Villiger oxidation of cyclobutanones

Bisulfenylation cyclobutanones

C4H8O2 Cyclobutanone - water

CYCLOBUTANONE 2- HYDROXY

CYCLOBUTANONE VIA SOLVOLYTIC

CYCLOBUTANONE VIA SOLVOLYTIC CYCLIZATION

Cyclization reactions cyclobutanones

Cycloaddition Cyclobutanone

Cycloaddition precursor cyclobutanone

Cycloaddition precursor cyclobutanones

Cycloaddition reactions chiral cyclobutanones

Cycloaddition reactions cyclobutanones

Cycloalkanones Cyclobutanones

Cyclobutadienes Cyclobutanones

Cyclobutanol Cyclobutanone

Cyclobutanol and Cyclobutanone Derivatives

Cyclobutanone O-benzoyloximes

Cyclobutanone aldol reactions

Cyclobutanone alkanone

Cyclobutanone carbon dioxide

Cyclobutanone cleavage

Cyclobutanone cyanohydrin

Cyclobutanone derivatives

Cyclobutanone derivatives, synthesis

Cyclobutanone dimethyl acetals

Cyclobutanone dimethyl dithioacetal

Cyclobutanone enolates

Cyclobutanone ketals

Cyclobutanone optically active

Cyclobutanone oxaspiropentane rearrangement

Cyclobutanone oximes, Beckmann

Cyclobutanone oximes, Beckmann rearrangements

Cyclobutanone pyrolysis

Cyclobutanone reaction with Grignard reagent

Cyclobutanone reduction

Cyclobutanone ring 7-lactones

Cyclobutanone selective reduction

Cyclobutanone synthesis, photochem

Cyclobutanone tosylhydrazone

Cyclobutanone, 2-hydroxy-: synthesis

Cyclobutanone, absorption

Cyclobutanone, absorption spectrum

Cyclobutanone, acidity

Cyclobutanone, diastereoselectivity

Cyclobutanone, hexafluoroene reaction

Cyclobutanone, homo-Favorskii rearrangement

Cyclobutanone, permethylreaction with a-selenoalkyllithium

Cyclobutanone, photolysis

Cyclobutanone, preparation

Cyclobutanone, radical cation

Cyclobutanone, singlet excited states

Cyclobutanone, substituted

Cyclobutanone, substituted Reformatsky reaction

Cyclobutanone, substituted enantioselective synthesis

Cyclobutanone, substituted synthesis

Cyclobutanone, synthesis

Cyclobutanone, unimolecular reaction

Cyclobutanone-ring expansion

Cyclobutanones

Cyclobutanones

Cyclobutanones 2+2] cycloaddition synthesis

Cyclobutanones => cyclopropyl

Cyclobutanones => ketenes

Cyclobutanones Baeyer-Villiger reaction

Cyclobutanones Baeyer-Villiger rearrangement

Cyclobutanones Vinylcyclobutanones

Cyclobutanones aldol reactions

Cyclobutanones alkyne insertion

Cyclobutanones chemoselective epoxidation

Cyclobutanones cyclopropanones

Cyclobutanones dimethyl acetals

Cyclobutanones enolates

Cyclobutanones epoxides

Cyclobutanones formation

Cyclobutanones from -cycloadditions

Cyclobutanones from enynes

Cyclobutanones from ketene complexes

Cyclobutanones in preparation of spirocyclic ketones

Cyclobutanones nickel-catalyzed reaction

Cyclobutanones oxidation

Cyclobutanones reactions with diazomethane

Cyclobutanones rearrangements

Cyclobutanones reduction

Cyclobutanones ring expansion

Cyclobutanones selective reduction

Cyclobutanones via ring expansion

Cyclobutanones via vinylcyclopropanes

Cyclobutanones, 2-vinyldivinyl ketones from

Cyclobutanones, 2-vinyldivinyl ketones from cyclization

Cyclobutanones, 2-vinyldivinyl ketones from synthesis

Cyclobutanones, 2-vinyldivinyl ketones from via Cope rearrangement

Cyclobutanones, 2-vinyldivinyl ketones from via ring expansion of cyclopropylcarbinols

Cyclobutanones, 4 + 2-cycloaddition

Cyclobutanones, asymmetric Baeyer-Villiger

Cyclobutanones, asymmetric Baeyer-Villiger reaction

Cyclobutanones, conformation

Cyclobutanones, cyclization

Cyclobutanones, from oxaspiropentanes

Cyclobutanones, preparation

Cyclobutanones, substituted

Cyclobutanones, substituted cyclization

Cyclobutanones, substituted synthesis

Cyclobutanones: synthesis

Cycloheptanone 2- cyclobutanone

Cyclooctanone 2- cyclobutanone

Cyclopentenone Annulation via Cyclobutanones

Cyclopropanols cyclobutanones

Determination of cyclobutanones

From cyclobutanones

Hydrolysis, of 5,9-dithiaspiro nonane to cyclobutanone

Ketenes, cyclobutanone from

Ketones cyclobutanones, from

Ketones from 1,3-Dithiane Cyclobutanone

L- cyclobutanone

Nickel cyclobutanones

Of cyclobutanones

Palladium cyclobutanones

Photochemistry of cyclobutanones

Rhodium cyclobutanones

Ring cyclobutanone

Secosulfenylation cyclobutanones

Single cyclobutanone

Spirocyclic cyclobutanone

Styrenes cyclobutanones from

Sulfoxide, methyl 2-chlorophenyl ring expansion with cyclobutanones

Syntheses of Cyclobutanones

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