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Isosorbide
Isosorbide is a bicyclic chemical compound from the group of diols and the oxygen-containing heterocycles, containing two fused furan rings. The starting material for isosorbide is D-sorbitol, which is obtained by catalytic hydrogenation of D-glucose, which is in turn produced by hydrolysis of starch. Isosorbide is discussed as a plant-based platform chemical from which biodegradable derivatives of various functionality can be obtained. In 2020, it was the 114th most commonly prescribed medication in the United States, with more than 5million prescriptions. Production Hydrogenation of glucose gives sorbitol. Isosorbide is obtained by acid-catalyzed dehydration of D- sorbitol which yields the monocyclic furanoid sorbitan, which in turn forms by further dehydration the bicyclic furofuran derivative isosorbide. The reaction gives about 70 to 80% isosorbide in addition to 30 to 20% of undesirable by-products which have to be removed costly by distillation, recrystallizatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isosorbide Reactions
Isosorbide is a Bicyclic compound, bicyclic chemical compound from the group of diols and the Heterocyclic compound, oxygen-containing heterocycles, containing two fused furan rings. The starting material for isosorbide is D-sorbitol, which is obtained by catalytic hydrogenation of D-glucose, which is in turn produced by hydrolysis of starch. Isosorbide is discussed as a plant-based platform chemical from which biodegradable Derivative (chemistry), derivatives of various Functionality (chemistry), functionality can be obtained. In 2020, it was the 114th most commonly prescribed medication in the United States, with more than 5million prescriptions. Production Hydrogenation of glucose gives sorbitol. Isosorbide is obtained by acid-catalyzed dehydration reaction, dehydration of D-sorbitol which yields the monocyclic furanoid sorbitan, which in turn forms by further dehydration the bicyclic furofuran derivative isosorbide. The reaction gives about 70 to 80% isosorbide in additio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sorbitan
Sorbitan is a mixture of isomeric organic compounds derived from the dehydration of sorbitol and is an intermediate in the conversion of sorbitol to isosorbide. Sorbitan is primarily used in the production of surfactants such as polysorbates; which are important emulsifying agents, with a total annual demand of more than 10000 tons in 2012. Synthesis Sorbitan is produced by the dehydration of sorbitol and is an intermediate in the conversion of sorbitol to isosorbide. The dehydration reaction usually produces sorbitan as a mixture of five- and six-membered cyclic ethers (1,4-anhydrosorbitol, 1,5-anhydrosorbitol and 1,4,3,6-dianhydrosorbitol) with the five-membered 1,4-anhydrosorbitol form being the dominate product. The rate of formation of sorbitan is typically greater than that of isosorbide, which allows it to be produced selectively, providing the reaction conditions are carefully controlled. The dehydration reaction has been shown to work even in the presence of excess wate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ketone
In organic chemistry, a ketone is a functional group 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)– (which contains a carbon-oxygen double bond C=O). The simplest ketone is acetone (where R and R' is methyl), with the formula . Many ketones are of great importance in biology and in industry. Examples include many sugars (ketoses), many steroids (e.g., testosterone), and the solvent acetone. Nomenclature and etymology The word ''ketone'' is derived from ''Aketon'', an old German word for ''acetone''. According to the rules of IUPAC nomenclature, ketone names are derived by changing the suffix ''-ane'' of the parent alkane to ''-anone''. Typically, the position of the carbonyl group is denoted by a number, but traditional nonsystematic names are still generally used for the most important ketones, for example acetone and benzophenone. These nonsystematic names are considere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endo-exo Isomerism
In organic chemistry, ''endo''–''exo'' isomerism is a special type of stereoisomerism found in organic compounds with a substituent on a bridged ring system. The prefix ''endo'' is reserved for the isomer with the substituent located closest, or "''syn''", to the longest bridge. The prefix ''exo'' is reserved for the isomer with the substituent located farthest, or "''anti''", to the longest bridge. Here "longest" and "shortest" refer to the number of atoms that comprise the bridge. This type of molecular geometry is found in norbornane systems such as dicyclopentadiene Dicyclopentadiene, abbreviated DCPD, is a chemical compound with formula C10H12. At room temperature, it is a white brittle wax, although lower purity samples can be straw coloured liquids. The pure material smells somewhat of soy wax or camphor .... The terms ''endo'' and ''exo'' are used in a similar sense in discussions of the stereoselectivity in Diels–Alder reactions. References * {{Navbox stereo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ChemSusChem
''ChemSusChem'' is a biweekly peer-reviewed scientific journal established in 2008 and published by Wiley-VCH on behalf of Chemistry Europe. The editor-in-chief is David J. Smith. The journal covers research at the interface of chemistry and sustainability, including contributions from materials science, chemical engineering, and biotechnology. It publishes full papers, communications, reviews, concepts, highlights, and viewpoints. According to the ''Journal Citation Reports'', the journal has a 2021 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as i ... of 9.140. References External links *{{Official website, https://chemistry-europe.onlinelibrary.wiley.com/journal/1864564x Chemistry Europe academic journals Wiley-VCH academic journals English-language journals C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tosylation
In organic chemistry, a toluenesulfonyl group (tosyl group, abbreviated Ts or Tos) is a univalent functional group with the chemical formula –. It consists of a tolyl group, –, joined to a sulfonyl group, ––, with the open valence on sulfur. This group is usually derived from the compound tosyl chloride, (abbreviated TsCl), which forms esters and amides of toluenesulfonic acid, (abbreviated TsOH). The para orientation illustrated (''p''-toluenesulfonyl) is most common, and by convention ''tosyl'' without a prefix refers to the ''p''-toluenesulfonyl group. The toluenesulfonate (or tosylate) group refers to the – (TsO–) group, with an additional oxygen attached to sulfur and open valence on an oxygen. In a chemical name, the term ''tosylate'' may either refer to the salts containing the anion of ''p''-toluenesulfonic acid, (M = alkali metal, , , etc), or it may refer to esters of ''p''-toluenesulfonic acid, TsOR (R = organyl group). Applications For SN2 reacti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Etherification
In organic chemistry, ethers are a class of compounds that contain an ether group—an oxygen atom connected to two alkyl or aryl groups. They have the general formula , where R and R′ represent the alkyl or aryl groups. Ethers can again be classified into two varieties: if the alkyl or aryl 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 C–O–C 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 in ethers, alcohols, and water is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Esterification
In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides are fatty acid esters of glycerol; they are important in biology, being one of the main classes of lipids and comprising the bulk of animal fats and vegetable oils. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. They perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Polyesters are important plastics, with monomers linked by ester moieties. Phosphoesters form the backbone of DNA molecules. Nitrate esters, such as nitroglycerin, are known for their explosive properties. '' Nomenclature Etymology The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitration
In organic chemistry, nitration is a general class of chemical processes for the introduction of a nitro group into an organic compound. The term also is applied incorrectly to the different process of forming nitrate esters between alcohols and nitric acid (as occurs in the synthesis of nitroglycerin). The difference between the resulting molecular structures of nitro compounds and nitrates is that the nitrogen atom in nitro compounds is directly bonded to a non-oxygen atom (typically carbon or another nitrogen atom), whereas in nitrate esters (also called organic nitrates), the nitrogen is bonded to an oxygen atom that in turn usually is bonded to a carbon atom (nitrito group). There are many major industrial applications of nitration in the strict sense; the most important by volume are for the production of nitroaromatic compounds such as nitrobenzene. Nitration reactions are notably used for the production of explosives, for example the conversion of guanidine to nitrog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Chemistry
Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.Clayden, J.; Greeves, N. and Warren, S. (2012) ''Organic Chemistry''. Oxford University Press. pp. 1–15. . Study of structure determines their structural formula. Study of properties includes physical and chemical properties, and evaluation of chemical reactivity to understand their behavior. The study of organic reactions includes the chemical synthesis of natural products, drugs, and polymers, and study of individual organic molecules in the laboratory and via theoretical ( in silico) study. The range of chemicals studied in organic chemistry includes hydrocarbons (compounds containing only carbon and hydrogen) as well as compounds based on carbon, but also containing other elements, especially oxygen, nitrogen, sulfur, phosphorus (included in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Hydroxy Group
In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy groups. Both the negatively charged anion , called hydroxide, and the neutral radical , known as the hydroxyl radical, consist of an unbonded hydroxy group. According to IUPAC definitions, the term ''hydroxyl'' refers to the hydroxyl radical () only, while the functional group is called a ''hydroxy group''. Properties Water, alcohols, carboxylic acids, and many other hydroxy-containing compounds can be readily deprotonated due to a large difference between the electronegativity of oxygen (3.5) and that of hydrogen (2.1). Hydroxy-containing compounds engage in intermolecular hydrogen bonding increasing the electrostatic attraction between molecules and thus to higher boiling and melting points than found for compounds that lack this func ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glaucoma
Glaucoma is a group of eye diseases that result in damage to the optic nerve (or retina) and cause vision loss. The most common type is open-angle (wide angle, chronic simple) glaucoma, in which the drainage angle for fluid within the eye remains open, with less common types including closed-angle (narrow angle, acute congestive) glaucoma and normal-tension glaucoma. Open-angle glaucoma develops slowly over time and there is no pain. Peripheral vision may begin to decrease, followed by central vision, resulting in blindness if not treated. Closed-angle glaucoma can present gradually or suddenly. The sudden presentation may involve severe eye pain, blurred vision, mid-dilated pupil, redness of the eye, and nausea. Vision loss from glaucoma, once it has occurred, is permanent. Eyes affected by glaucoma are referred to as being glaucomatous. Risk factors for glaucoma include increasing age, high pressure in the eye, a family history of glaucoma, and use of steroid medication. F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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