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Ethers
In organic chemistry, ethers are a class of compounds that contain an ether group, a single oxygen atom bonded to two separate carbon atoms, each part of an organyl group (e.g., alkyl or aryl). They have the general formula , where R and R′ represent the organyl groups. Ethers can again be classified into two varieties: if the organyl groups are the same on both sides of the oxygen atom, then it is a simple or symmetrical ether, whereas if they are different, the ethers are called mixed or unsymmetrical ethers. A typical example of the first group is the solvent and anaesthetic diethyl ether, commonly referred to simply as "ether" (). Ethers are common in organic chemistry and even more prevalent in biochemistry, as they are common linkages in carbohydrates and lignin. Structure and bonding Ethers feature bent linkages. In dimethyl ether, the bond angle is 111° and C–O distances are 141 pm. The barrier to rotation about the C–O bonds is low. The bonding of oxygen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enol Ether
In organic chemistry an enol ether is an alkene with an alkoxy substituent. The general structure is R2C=CR-OR where R = H, alkyl or aryl. A common subfamily of enol ethers are vinyl ethers, with the formula ROCH=CH2. Important enol ethers include the reagent 3,4-dihydropyran and the monomers methyl vinyl ether and ethyl vinyl ether. Reactions and uses Akin to enamines, enol ethers are electron-rich alkenes by virtue of the electron-donation from the heteroatom via pi-bonding. Enol ethers have oxonium ion character. By virtue of their bonding situation, enol ethers display distinctive reactivity. In comparison with simple alkenes, enol ethers exhibit enhanced susceptibility to attack by electrophiles such as Bronsted acids. Similarly, they undergo inverse demand Diels-Alder reactions. The reactivity of enol ethers is highly dependent on the presence of substituents alpha to oxygen. The vinyl ethers are susceptible to polymerization to give polyvinyl ethers. They also re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dipropyl Ether
Dipropyl ether is the symmetrical ether of two ''n''-propyl groups. It is a colorless, flammable liquid with a sweet odor typical of ethers. Preparation Acid catalyzed ether synthesis Dipropyl ether can be synthesized by reacting two molecules of 1-Propanol, ''n''-propanol in the presence of p-toluenesulfonic acid (a strong acid) and heat, in the same way other symmetrical ethers may be formed. Williamson ether synthesis This ether may also be prepared by way of the Williamson ether synthesis in which ''n''-propoxide, the conjugate base of ''n''-propanol, is reacted with an ''n''-propyl halide: : Safety As is typical of ethers, dipropyl ether may slowly form explosive organic peroxides over long periods in storage. Antioxidants such as butylated hydroxytoluene are often added to ethers to prevent this process. Due to the shock and light sensitive nature of organic peroxides, dipropyl ether should never be boiled or evaporated to dryness. This concentrates peroxides that ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solvent
A solvent (from the Latin language, Latin ''wikt:solvo#Latin, solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a Solution (chemistry), solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for Chemical polarity#Polarity of molecules, polar molecules, and the most common solvent used by living things; all the ions and proteins in a Cell (biology), cell are dissolved in water within the cell. Major uses of solvents are in paints, paint removers, inks, and dry cleaning. Specific uses for Organic compound, organic solvents are in dry cleaning (e.g. tetrachloroethylene); as paint thinners (toluene, turpentine); as nail polish removers and solvents of glue (acetone, methyl acetate, ethyl acetate); in spot removers (hexane, petrol ether); in detergents (D-limonene, citrus terpenes); and in perfumes (ethanol). Solvents find various applications in chemical, pharmaceutical, oil, and gas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diethyl Ether
Diethyl ether, or simply ether, is an organic compound with the chemical formula , sometimes abbreviated as . It is a colourless, highly Volatility (chemistry), volatile, sweet-smelling ("ethereal odour"), extremely flammable liquid. It belongs to the ether class of organic compounds. It is a common solvent and was formerly used as a general anesthetic. Production Most diethyl ether is produced as a byproduct of the vapor-phase Hydration reaction, hydration of ethylene to make ethanol. This process uses solid-supported phosphoric acid Catalysis, catalysts and can be adjusted to make more ether if the need arises: Vapor-phase Dehydration reaction, dehydration of ethanol over some Aluminium oxide, alumina catalysts can give diethyl ether yields of up to 95%. : Diethyl ether can be prepared both in laboratories and on an industrial scale by the acid ether synthesis. Uses The dominant use of diethyl ether is as a solvent. One particular application is in the production of cell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimethyl Ether
Dimethyl ether (DME; also known as methoxymethane) is the organic compound with the formula CH3OCH3, (sometimes ambiguously simplified to C2H6O as it is an isomer of ethanol). The simplest ether, it is a colorless gas that is a useful precursor to other organic compounds and an aerosol propellant that is currently being demonstrated for use in a variety of fuel applications. Dimethyl ether was first synthesised by Jean-Baptiste Dumas and Eugene Péligot in 1835 by distillation of methanol and sulfuric acid. Production Approximately 50,000 tons were produced in 1985 in Western Europe by dehydration of methanol:Manfred Müller, Ute Hübsch, "Dimethyl Ether" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. : The required methanol is obtained from synthesis gas ( syngas). Other possible improvements call for a dual catalyst system that permits both methanol synthesis and dehydration in the same process unit, with no methanol isolation and purificatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methoxy
In organic chemistry, a methoxy group is the functional group consisting of a methyl group bound to oxygen. This alkoxy group has the formula . On a benzene ring, the Hammett equation classifies a methoxy substituent at the ''para'' position as an electron-donating group, but as an electron-withdrawing group if at the ''meta'' position. At the ''ortho'' position, steric effects are likely to cause a significant alteration in the Hammett equation prediction, which otherwise follows the same trend as that of the ''para'' position. Occurrence The simplest of methoxy compounds are methanol and dimethyl ether. Other methoxy ethers include anisole and vanillin. Many metal alkoxides contain methoxy groups, such as tetramethyl orthosilicate and titanium methoxide. Esters with a methoxy group can be referred to as methyl esters, and the —COOCH3 substituent is called a methoxycarbonyl. Biosynthesis In nature, methoxy groups are found on nucleosides subjected to 2′-''O''-meth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxygen
Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), nonmetal, and a potent oxidizing agent that readily forms oxides with most elements as well as with other chemical compound, compounds. Oxygen is abundance of elements in Earth's crust, the most abundant element in Earth's crust, making up almost half of the Earth's crust in the form of various oxides such as water, carbon dioxide, iron oxides and silicates.Atkins, P.; Jones, L.; Laverman, L. (2016).''Chemical Principles'', 7th edition. Freeman. It is abundance of chemical elements, the third-most abundant element in the universe after hydrogen and helium. At standard temperature and pressure, two oxygen atoms will chemical bond, bind covalent bond, covalently to form dioxygen, a colorless and odorless diatomic gas with the chemical formula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methoxyethane
Methoxyethane, also known as ethyl methyl ether, is a colorless gaseous ether with the formula . Unlike the related dimethyl ether and diethyl ether, which are widely used and studied, this mixed alkyl ether has no current applications. It is a structural isomer of isopropyl alcohol Isopropyl alcohol (IUPAC name propan-2-ol and also called isopropanol or 2-propanol) is a colorless, flammable, organic compound with a pungent alcoholic odor. Isopropyl alcohol, an organic polar molecule, is miscible in water, ethanol, an .... Its utility as an anesthetic and solvent have been investigated. References Dialkyl ethers Ether solvents {{Ether-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anisole
Anisole, or methoxybenzene, is an organic compound with the formula . It is a colorless liquid with a smell reminiscent of anise seed, and in fact many of its derivatives are found in natural and artificial fragrances. The compound is mainly made synthetically and is a precursor to other synthetic compounds. Structurally, it is an ether () with a methyl () and phenyl () group attached. Anisole is a standard reagent of both practical and pedagogical value. Reactivity Anisole undergoes electrophilic aromatic substitution reaction at a faster speed than benzene, which in turn reacts more quickly than nitrobenzene. The methoxy group is an ortho/para directing group, which means that electrophilic substitution preferentially occurs at these three sites. The enhanced nucleophilicity of anisole vs. benzene reflects the influence of the methoxy group, which renders the ring more electron-rich. The methoxy group strongly affects the pi cloud of the ring as a mesomeric electron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimethoxyethane
Dimethoxyethane, also known as glyme, monoglyme, dimethyl glycol, ethylene glycol dimethyl ether, dimethyl cellosolve, and DME, is a colorless, aprotic, and liquid ether that is used as a solvent, especially in batteries. Dimethoxyethane is miscible with water. Production Monoglyme is produced industrially by the reaction of dimethylether with ethylene oxide: :CH3OCH3 + CH2CH2O → CH3OCH2CH2OCH3 Applications as solvent and ligand left, 144px, Structure of the coordination complex NbCl3(dimethoxyethane)(3-hexyne). Together with a high-permittivity solvent (e.g. propylene carbonate), dimethoxyethane is used as the low-viscosity component of the solvent for electrolytes of lithium batteries. In the laboratory, DME is used as a coordinating solvent. Dimethoxyethane is often used as a higher-boiling-point alternative to diethyl ether and tetrahydrofuran. Dimethoxyethane acts as a bidentate ligand for some metal cations. It is therefore often used in organometallic chemist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Synthesis
Organic synthesis is a branch of chemical synthesis concerned with the construction of organic compounds. Organic compounds are molecules consisting of combinations of covalently-linked hydrogen, carbon, oxygen, and nitrogen atoms. Within the general subject of organic synthesis, there are many different types of synthetic routes that can be completed including total synthesis, Enantioselective synthesis, stereoselective synthesis, automated synthesis, and many more. Additionally, in understanding organic synthesis it is necessary to be familiar with the methodology, techniques, and applications of the subject. Total synthesis A total synthesis refers to the complete chemical synthesis of molecules from simple, Precursor (chemistry), natural precursors. Total synthesis is accomplished either via a linear or convergent approach. In a Linear synthesis, ''linear'' synthesis—often adequate for simple structures—several steps are performed sequentially until the molecule is com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
