Names | |
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Preferred IUPAC name Cyclobutanone | |
Identifiers | |
3D model (JSmol) | |
ChemSpider | |
ECHA InfoCard | 100.013.405 |
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
C4H6O | |
Molar mass | 70.091 g·mol−1 |
Appearance | Colorless liquid |
Density | 0.9547 g/cm3 (0 °C) [1] |
Melting point | −50.9 °C (−59.6 °F; 222.2 K) [1] |
Boiling point | 99.75 °C (211.55 °F; 372.90 K) [1] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Cyclobutanone is an organic compound with molecular formula (CH2)3CO. It is a four-membered cyclic ketone (cycloalkanone). It is a colorless volatile liquid at room temperature. Since cyclopropanone is highly sensitive, cyclobutanone is the smallest easily handled cyclic ketone.
The Russian chemist Nikolai Kischner first prepared cyclobutanone in a low yield from cyclobutanecarboxylic acid. [2] [3] Kischner's process, involving several steps, is cumbersome and inefficient; more efficient, high-yielding syntheses have since been developed. [4]
One strategy involves degradation of five-carbon building blocks. For example, the oxidative decarboxylation of cyclobutanecarboxylic acid was improved by the use of other reagents and methods.
A newer, more efficient preparation of cyclobutanone was found by P. Lipp and R. Köster in which a solution of diazomethane in diethyl ether is reacted with ketene. [5] This reaction is based on a ring expansion of the cyclopropanone intermediate initially formed, wherein molecular nitrogen is split off:
The reaction mechanism was confirmed by a reaction using 14C-labeled diazomethane. [6]
Another synthesis of cyclobutanone involves lithium-catalyzed rearrangement of oxaspiropentane, which is formed by epoxidation of the easily accessible methylenecyclopropane: [7] [8]
Cyclobutanone can also be prepared in a two step procedure by dialkylation of 1,3-dithiane with 1-bromo-3-chloropropane followed by deprotection to the ketone with mercuric chloride (HgCl2) and cadmium carbonate (CdCO3). [9]
Cyclobutanones are the intermediates of the homo-Favorskii rearrangement, and can be isolated when nucleophiles are absent, as in the synthesis of kelsoene:
At about 350 °C, cyclobutanone decomposes into ethylene and ketene. [10] The activation energy for this [2+2] cycloelimination is 52 kcal/mol. The reverse reaction, the [2+2] cycloaddition of ketene and ethylene, has never been observed.
Other cyclic ketones:
In organic chemistry, a ketone is an organic compound with the structure R−C(=O)−R', where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group −C(=O)−. The simplest ketone is acetone, with the formula (CH3)2CO. Many ketones are of great importance in biology and in industry. Examples include many sugars (ketoses), many steroids, and the solvent acetone.
In organic chemistry, an imine is a functional group or organic compound containing a carbon–nitrogen double bond. The nitrogen atom can be attached to a hydrogen or an organic group (R). The carbon atom has two additional single bonds. Imines are common in synthetic and naturally occurring compounds and they participate in many reactions.
Diazomethane is an organic chemical compound with the formula CH2N2, discovered by German chemist Hans von Pechmann in 1894. It is the simplest diazo compound. In the pure form at room temperature, it is an extremely sensitive explosive yellow gas; thus, it is almost universally used as a solution in diethyl ether. The compound is a popular methylating agent in the laboratory, but it is too hazardous to be employed on an industrial scale without special precautions. Use of diazomethane has been significantly reduced by the introduction of the safer and equivalent reagent trimethylsilyldiazomethane.
Clemmensen reduction is a chemical reaction described as a reduction of ketones or aldehydes to alkanes using zinc amalgam and concentrated hydrochloric acid (HCl). This reaction is named after Erik Christian Clemmensen, a Danish-American chemist.
The Vilsmeier–Haack reaction (also called the Vilsmeier reaction) is the chemical reaction of a substituted formamide (1) with phosphorus oxychloride and an electron-rich arene (3) to produce an aryl aldehyde or ketone (5):
In organic chemistry, the Arndt–Eistert reaction is the conversion of a carboxylic acid to its homologue. Named for the German chemists Fritz Arndt (1885–1969) and Bernd Eistert (1902–1978), the method entails treating an acid chlorides with diazomethane. It is a popular method of producing β-amino acids from α-amino acids.
The Favorskii rearrangement is principally a rearrangement of cyclopropanones and α-halo ketones that leads to carboxylic acid derivatives. In the case of cyclic α-halo ketones, the Favorskii rearrangement constitutes a ring contraction. This rearrangement takes place in the presence of a base, sometimes hydroxide, to yield a carboxylic acid, but usually either an alkoxide base or an amine to yield an ester or an amide, respectively. α,α'-Dihaloketones eliminate HX under the reaction conditions to give α,β-unsaturated carbonyl compounds.Note that trihalomethyl ketone substrates will result in haloform and carboxylate formation via the haloform reaction instead.
In organic chemistry, an α-halo ketone is a functional group consisting of a ketone group or more generally a carbonyl group with an α-halogen substituent. α-Halo ketones are alkylating agents. Prominent α-halo ketones include phenacyl bromide and chloroacetone.
A dithiane is a heterocyclic compound composed of a cyclohexane core structure wherein two methylene bridges are replaced by sulfur. The three isomeric parent heterocycles are 1,2-dithiane, 1,3-dithiane and 1,4-dithiane. They are all colorless solids.
Diisopropylamine is a secondary amine with the chemical formula (Me2CH)2NH (Me = methyl). Diisopropylamine is a colorless liquid with an ammonia-like odor. Its lithium derivative, lithium diisopropylamide, known as LDA is a widely used reagent.
Cyclopropanone is an organic compound with molecular formula (CH2)2CO consisting of a cyclopropane carbon framework with a ketone functional group. The parent compound is labile, being highly sensitive toward even weak nucleophiles. Surrogates of cyclopropanone include the ketals.
The Schotten–Baumann reaction is a method to synthesize amides from amines and acid chlorides:
The Glaser coupling is a type of coupling reaction. It is by far the oldest acetylenic coupling and is based on cuprous salts like copper(I) chloride or copper(I) bromide and an additional oxidant like oxygen. The base in its original scope is ammonia. The solvent is water or an alcohol. The reaction was first reported by Carl Andreas Glaser in 1869. He suggested the following process for his way to diphenylbutadiyne:
The Hoesch reaction or Houben–Hoesch reaction is an organic reaction in which a nitrile reacts with an arene compound to form an aryl ketone. The reaction is a type of Friedel-Crafts acylation with hydrogen chloride and a Lewis acid catalyst.
Methylenecyclopropane is an organic compound with the formula (CH2)2C=CH2. It is a hydrocarbon which, as the name suggests, is derived from the addition of a methylene substituent to a cyclopropane ring. It is a colourless, easily condensed gas that is used as a reagent in organic synthesis.
The Buchner–Curtius–Schlotterbeck reaction is the reaction of aldehydes or ketones with aliphatic diazoalkanes to form homologated ketones. It was first described by Eduard Buchner and Theodor Curtius in 1885 and later by Fritz Schlotterbeck in 1907. Two German chemists also preceded Schlotterbeck in discovery of the reaction, Hans von Pechmann in 1895 and Viktor Meyer in 1905. The reaction has since been extended to the synthesis of β-keto esters from the condensation between aldehydes and diazo esters. The general reaction scheme is as follows:
The Corey–Seebach reaction, or Seebach Umpolung is a name reaction of organic chemistry that allows for acylation by converting aldehydes into lithiated 1,3-dithianes. The lithiated 1,3-dithianes serves as an acyl anion equivalent, undergoing alkylation with electrophiles. The reaction is named in honor of its discoverers, Elias J. Corey and Dieter Seebach.
Methallyl chloride is the organic compound with the formula CH2=C(CH3)CH2Cl. It is a colorless liquid and a lacrymator. Its properties are similar to those of allyl chloride. It is a strong alkylating agent used to install isobutenyl groups.
In organic chemistry, methylenation is a chemical reaction that inserts a methylene group into a chemical compound:
1,3-Dithiolane is the organosulfur compound with the formula CH2S2C2H4. Also classified as a heterocycle related cyclopentane by replacing two methylene bridges with thioether groups. It is an isomer of 1,2-dithiolane.1,3-Dithiolanes are compounds where one or more H atoms of the parent 1,3-dithiolane are replaced by other groups. These species are more widely studied.
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: CS1 maint: multiple names: authors list (link); Collected Volumes, vol. 6, p. 320.