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Guerbet Reaction
The Guerbet reaction, named after Marcel Guerbet (1861–1938), is an organic reaction that converts a primary Alcohol (chemistry), alcohol into its β-alkylated Dimer (chemistry), dimer Alcohol (chemistry), alcohol with loss of one equivalent of water. The process is of interest because it converts simple inexpensive feedstocks into more valuable products. Its main disadvantage is that the reaction produces mixtures. Scope and applications The original 1899 publication concerned the conversion of N-Butanol, ''n''-butanol to 2-ethylhexanol. 2-ethylhexanol is however more easily prepared by alternative methods (from butyraldehyde by aldol condensation). Instead, the Guerbet reaction is mainly applied to fatty alcohols to afford oily products, which are called Guerbet alcohols. They are of commercial interest to as components of cosmetics, plasticizers, and related applications. The reaction is conducted in the temperature range 180-360 °C, often in a sealed reactor. The reac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Reaction
Organic reactions are chemical reactions involving organic compounds. The basic organic chemistry reaction types are addition reactions, elimination reactions, substitution reactions, pericyclic reactions, rearrangement reactions, mechanistic organic photochemistry, photochemical reactions and organic redox reaction, redox reactions. In organic synthesis, organic reactions are used in the construction of new organic molecules. The production of many man-made chemicals such as drugs, plastics, food additives, fabrics depend on organic reactions. The oldest organic reactions are combustion of organic fuels and saponification of fats to make soap. Modern organic chemistry starts with the Wöhler synthesis in 1828. In the history of the Nobel Prize in Chemistry awards have been given for the invention of specific organic reactions such as the Grignard reaction in 1912, the Diels–Alder reaction in 1950, the Wittig reaction in 1979 and olefin metathesis in 2005. Classifications Organ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reaction Mechanism
In chemistry, a reaction mechanism is the step by step sequence of elementary reactions by which overall chemical reaction occurs. A chemical mechanism is a theoretical conjecture that tries to describe in detail what takes place at each stage of an overall chemical reaction. The detailed steps of a reaction are not observable in most cases. The conjectured mechanism is chosen because it is thermodynamically feasible and has experimental support in isolated intermediates (see next section) or other quantitative and qualitative characteristics of the reaction. It also describes each reactive intermediate, activated complex, and transition state, which bonds are broken (and in what order), and which bonds are formed (and in what order). A complete mechanism must also explain the reason for the reactants and catalyst used, the stereochemistry observed in reactants and products, all products formed and the amount of each. The electron or arrow pushing method is often used in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2-Ethylhexanol
2-Ethylhexanol (abbreviated 2-EH) is an organic compound with the chemical formula . It is a branched, eight-carbon chiral alcohol. It is a colorless liquid that is poorly soluble in water but soluble in most organic solvents. It is produced on a large scale (>2,000,000,000 kg/y) for use in numerous applications such as solvents, flavors, and fragrances and especially as a precursor for production of other chemicals such as emollients and plasticizers. It is encountered in plants, fruits, and wines. The odor has been reported as "heavy, earthy, and slightly floral" for the R enantiomer and "a light, sweet floral fragrance" for the S enantiomer. Properties and applications The branching in 2-ethylhexanol inhibits crystallization. Esters of 2-ethylhexanol are similarly affected, which together with low volatility, is the basis of applications in the production of plasticizers and lubricants, where its presence helps reduce viscosity and lower freezing points. Because 2-ethylhexan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2-Ethyl-1-butanol
2-Ethyl-1-butanol (IUPAC name: 2-ethylbutan-1-ol) is an organic chemical compound. It can be used to facilitate the separation of ethanol from water, which forms an azeotrope that otherwise limits the maximum ethanol concentration. Reactions 2-Ethyl-1-butanol is manufactured industrially by the aldol condensation of acetaldehyde and butyraldehyde, followed by hydrogenation. It may also be prepared by the Guerbet reaction. Properties and applications The branching in 2-ethyl-1-butanol makes it harder to crystallize due to packing disruption, which results in a very low freezing point. Esters of 2-ethyl-1-butanol are similarly effected and it therefore finds application as a feedstock in the production of plasticizers and lubricants, where its presence helps reduce viscosity and lower freezing points. See also *2-Ethylhexanol 2-Ethylhexanol (abbreviated 2-EH) is an organic compound with the chemical formula . It is a branched, eight-carbon chiral alcohol. It is a colorless liquid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxo Alcohol
Oxo alcohols are alcohols that are prepared by adding carbon monoxide (CO) and hydrogen (usually combined as synthesis gas) to an olefin to obtain an aldehyde using the hydroformylation reaction and then hydrogenating the aldehyde to obtain the alcohol. An intermediate step of adding two aldehydes together to obtain a larger aldehyde (the aldol condensation reaction) can precede the hydrogenation. Long chain oxo-alcohols are often prepared using alpha-olefins from the Shell higher olefin process, to give secondary alcohols such as isodecyl alcohol. Key oxo alcohols that are sold in commerce include the following: * 2-Methyl-2-butanol (2M2B) * ''n''-Butanol * 2-Ethylhexanol * 2-Propylheptanol * Isononyl alcohol * Isodecyl alcohol Key manufacturers of oxo alcohols include the following companies: * BASF * Dow Chemical Company * Eastman Chemical Company * ExxonMobil * Grupa Azoty * Petronas * Sasol * SABIC Oxo alcohols are used as solvents and are reacted with phthalic anh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tishchenko Reaction
The Tishchenko reaction is an organic chemical reaction that involves disproportionation of an aldehyde in the presence of an alkoxide. The reaction is named after Russian organic chemist Vyacheslav Tishchenko, who discovered that aluminium alkoxides are effective catalysts for the reaction. In the related Cannizzaro reaction, the base is sodium hydroxide and then the oxidation product is a carboxylic acid and the reduction product is an alcohol. History The reaction involving benzaldehyde was discovered by Claisen using sodium benzylate as base. The reaction produces benzyl benzoate. Enolizable aldehydes are not amenable to Claisen's conditions. Vyacheslav Tishchenko discovered that aluminium alkoxides allowed the conversion of enolizable aldehydes to esters. Examples * The Tishchenko reaction of acetaldehyde gives the commercially important solvent ethyl acetate. The reaction is catalyzed by aluminium alkoxides. * The Tishchenko reaction is used to obtain isobutyl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carboxylic Acid
In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an Substituent, R-group. The general formula of a carboxylic acid is often written as or , sometimes as with R referring to an organyl group (e.g., alkyl, alkenyl, aryl), or hydrogen, or other groups. Carboxylic acids occur widely. Important examples include the amino acids and fatty acids. Deprotonation of a carboxylic acid gives a carboxylate anion. Examples and nomenclature Carboxylic acids are commonly identified by their trivial names. They often have the suffix ''-ic acid''. IUPAC-recommended names also exist; in this system, carboxylic acids have an ''-oic acid'' suffix. For example, butyric acid () is butanoic acid by IUPAC guidelines. For nomenclature of complex molecules containing a carboxylic acid, the carboxyl can be considered position one of the parent chain even if there are other substituents, such as 3-chloropropanoic acid. Alternately, it can be named ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disproportionation
In chemistry, disproportionation, sometimes called dismutation, is a redox reaction in which one compound of intermediate oxidation state converts to two compounds, one of higher and one of lower oxidation state. The reverse of disproportionation, such as when a compound in an intermediate oxidation state is formed from precursors of lower and higher oxidation states, is called ''comproportionation'', also known as ''symproportionation''. More generally, the term can be applied to any desymmetrizing reaction where two molecules of one type react to give one each of two different types: : This expanded definition is not limited to redox reactions, but also includes some molecular autoionization reactions, such as the self-ionization of water. In contrast, some authors use the term ''redistribution'' to refer to reactions of this type (in either direction) when only ligand exchange but no redox is involved and distinguish such processes from disproportionation and comproportionati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cannizzaro Reaction
The Cannizzaro reaction, named after its discoverer Stanislao Cannizzaro, is a chemical reaction which involves the base-induced disproportionation of two molecules of a non-enolizable aldehyde to give a primary alcohol and a carboxylic acid. : Cannizzaro first accomplished this transformation in 1853, when he obtained benzyl alcohol and potassium benzoate from the treatment of benzaldehyde with potash (potassium carbonate). More typically, the reaction would be conducted with sodium hydroxide or potassium hydroxide, giving the sodium or potassium carboxylate salt of the carboxylic-acid product: :2 C6H5CHO + KOH → C6H5CH2OH + C6H5COOK The process is a redox reaction involving transfer of a hydride from one substrate molecule to the other: one aldehyde is oxidized to form the acid, the other is reduced to form the alcohol. Mechanism The reaction involves a nucleophilic acyl substitution on an aldehyde, with the leaving group concurrently attacking another aldehy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guerbet ReactionMechanism
Guerbet () is a France-based manufacturer of contrast agents used in medical imaging. The company was founded in 1926 by André Guerbet, the son of Marcel Guerbet who in 1901 discovered Lipiodol – the first iodinated X-ray contrast agent. In 2017 Guerbet’s revenues were €807.1 million. It employs over 2,700 people worldwide and has manufacturing facilities in France, Ireland, Canada, Macedonia, the United States and Brazil. The company’s headquarters, formerly located in Villepinte, is currently located in Chicago, and its shares are included in the NASDAQ stock index. In July 2015, Guerbet announced the takeover of a portion of Mallinckrodt Mallinckrodt Pharmaceuticals plc is an American-Irish domiciled manufacturer of specialty pharmaceuticals (namely, adrenocorticotropic hormone), generic drugs and imaging agents. In 2017, it generated 90% of its sales from the U.S. healthcare s ...'s contrast media and application systems divisions. The acquisition was completed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
