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Allene Oxide
In organic chemistry, an allene oxide is an epoxide of an allene. The parent allene oxide is CH2=C(O)CH2 (CAS registry number, RN 40079-14-9), a rare and reactive species of only theoretical interest. Typical allene oxides require steric protection for their isolation. Certain derivatives can be prepared by epoxidation of the allenes with peracetic acid. Allene oxides tend to rearrange to cyclopropanones. Despite the esoteric character of synthetic allene oxides, allene oxides occur naturally. They are intermediates in the chemical defense of some plants against attack by herbivores. Specifically, a hydroperoxide of linolenic acid is the substrate for the enzyme allene oxide synthase. The resulting allene oxide in turn is converted by allene oxide cyclase to jasmonic acid. Nevertheless, allene oxides are extremely unstable even in biological contexts, decomposing with a half-life of approximately 15-30 s. References {{Reflist Epoxides Alkenes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Organic Chemistry
Organic chemistry is a subdiscipline within chemistry involving the science, scientific study of the structure, properties, and reactions of organic compounds and organic matter, 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 property, physical and Chemical property, chemical properties, and evaluation of Reactivity (chemistry), chemical reactivity to understand their behavior. The study of organic reactions includes the organic synthesis, 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 chemistry includes hydrocarbons (compounds containing only carbon and hydrogen) as well as compounds based on carbon, but a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Allene
In organic chemistry, allenes are organic compounds in which one carbon atom has double bonds with each of its two adjacent carbon atoms (, where R is hydrogen, H or some organyl group). Allenes are classified as diene#Classes, cumulated dienes. The parent compound of this class is propadiene (), which is itself also called ''allene''. A group of the structure is called allenyl, while a substituent attached to an allene is referred to as an allenic substituent (R is H or some alkyl group). In analogy to Allyl group, allylic and Propargyl group, propargylic, a substituent attached to a saturated carbon α (i.e., directly adjacent) to an allene is referred to as an allenylic substituent. While allenes have two consecutive ('cumulated') double bonds, compounds with three or more cumulated double bonds are called cumulenes. History For many years, allenes were viewed as curiosities but thought to be synthetically useless and difficult to prepare and to work with.The Chemistry of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Epoxidation
In organic chemistry, an epoxide is a cyclic ether, where the ether forms a three-atom ring: two atoms of carbon and one atom of oxygen. This triangular structure has substantial ring strain, making epoxides highly reactive, more so than other ethers. They are produced on a large scale for many applications. In general, low molecular weight epoxides are colourless and nonpolar, and often volatile. Nomenclature A compound containing the epoxide functional group can be called an epoxy, epoxide, oxirane, and ethoxyline. Simple epoxides are often referred to as oxides. Thus, the epoxide of ethylene (C2H4) is ethylene oxide (C2H4O). Many compounds have trivial names; for instance, ethylene oxide is called "oxirane". Some names emphasize the presence of the epoxide functional group, as in the compound ''1,2-epoxyheptane'', which can also be called ''1,2-heptene oxide''. A polymer formed from epoxide precursors is called an ''epoxy''. However, few if any of the epoxy groups in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Peracetic Acid
Peracetic acid (also known as peroxyacetic acid, or Percidine) is an organic compound with the formula CH3CO3H. This peroxy acid is a colorless liquid with a characteristic acrid odor reminiscent of acetic acid. It can be highly corrosive. Peracetic acid is a weaker acid than the parent acetic acid, with a p''K''a of 8.2. Production Peracetic acid is produced industrially by the autoxidation of acetaldehyde: :O2 + CH3CHO → CH3CO3H Peracetic acid is conventionally prepared by combining acetic acid and hydrogen peroxide with homogeneous acid catalysts (e.g., sulfuric acid), which facilitate the reaction and achieve equilibrium between the reagents and product: :H2O2 + CH3CO2H CH3CO3H + H2O While it is feasible to create peracetic acid by combining consumer-grade vinegar (5% acetic acid) and hydrogen peroxide (3%) without an acid catalyst, the low concentration of reagents will result in a slow reaction rate at room temperature. Extrapolating from published reaction rates, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Cyclopropanone
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. Preparation Cyclopropanone has been prepared by reaction of ethenone, ketene with diazomethane in an unreactive solvent such as dichloromethane. These solutions are stable at −78 °C. In the presence of protic reagents such as carboxylic acids, primary and secondary amines, and alcohols, cyclopropanone converts to adducts, which are often isolatable at room temperature: :(CH2)2CO + X-H → (CH2)2C(X)(OH) (X-H = R2N-H, HO-H, RO-H) Structure The C3O atoms are coplanar. As deduced from the Microwave spectroscopy, microwave spectrum, the H2C-CH2 bond length of 157.5 picometer, pm is unusually long. By contrast, the C-C bond lengths in cyclopropane are 151 pm. The C=O bond le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Hydroperoxide
Hydroperoxides or peroxols are Chemical compound, compounds of the form ROOH, where R stands for any group, typically Organic compound, organic, which contain the hydroperoxy functional group (). Hydroperoxide also refers to the hydroperoxide anion () and its Salt (chemistry), salts, and the neutral hydroperoxyl, hydroperoxyl radical (•OOH) consist of an unbond hydroperoxy group. When R is organic, the compounds are called organic hydroperoxides. Such compounds are a subset of organic peroxides, which have the formula ROOR. Organic hydroperoxides can either intentionally or unintentionally initiate explosive polymerisation in materials with saturated bond, saturated chemical bonds. Properties The bond length in peroxides is about 1.45 Ångström, Å, and the angles (R = Hydrogen, H, Carbon, C) are about 110° (water-like). Characteristically, the dihedral angles are about 120°. The bond is relatively weak, with a bond dissociation energy of , less than half the strength ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Linolenic Acid
Linolenic acid is a type of naturally-occurring fatty acid. It can refer to either of two octadecatrienoic acids (i.e. with an 18-carbon chain and three double bonds, which are found in the '' cis'' configuration), or a mixture of the two. Linolenate (in the form of triglyceride esters of linolenic acid) is often found in vegetable oils; traditionally, such fatty acylates are reported as the fatty acids: *α-Linolenic acid, an omega-3 (n-3) fatty acid * γ-Linolenic acid, an omega-6 (n-6) fatty acid See also * Linoleic acid Linoleic acid (LA) is an organic compound with the formula . Both alkene groups () are ''cis''. It is a fatty acid sometimes denoted 18:2 (n−6) or 18:2 ''cis''-9,12. A linoleate is a salt or ester of this acid. Linoleic acid is a polyunsat ..., the similarly named essential fatty acid References {{chemistry index Alkenoic acids Aromatase inhibitors Fatty acids Essential fatty acids Essential nutrients ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Allene Oxide Synthase
In organic chemistry, allenes are organic compounds in which one carbon atom has double bonds with each of its two adjacent carbon atoms (, where R is H or some organyl group). Allenes are classified as cumulated dienes. The parent compound of this class is propadiene (), which is itself also called ''allene''. A group of the structure is called allenyl, while a substituent attached to an allene is referred to as an allenic substituent (R is H or some alkyl group). In analogy to allylic and propargylic, a substituent attached to a saturated carbon α (i.e., directly adjacent) to an allene is referred to as an allenylic substituent. While allenes have two consecutive ('cumulated') double bonds, compounds with three or more cumulated double bonds are called cumulenes. History For many years, allenes were viewed as curiosities but thought to be synthetically useless and difficult to prepare and to work with.The Chemistry of the Allenes (vol. 1−3); Landor, S. R., Ed.; cademi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Allene Oxide Cyclase
In enzymology, an allene-oxide cyclase () is an enzyme that belongs to the family of isomerases, specifically a class of other intramolecular oxidoreductases. The systematic name of this enzyme class is (9''Z'')-(13''S'')-12,13-epoxyoctadeca-9,11,15-trienoate isomerase (cyclizing). The allene oxide of linolenic acid (i.e., (9''Z'')-(13''S'')-12,13-epoxyoctadeca-9,11,15-trienoate) is converted by allene oxide cyclase to jasmonic acid ((15''Z'')-12-oxophyto-10,15-dienoate). Structural studies As of late 2007, 6 structures A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such as ... have been solved for this class of enzymes, with PDB accession codes , , , , , and . References * EC 5.3.99 Enzymes of known structure {{isomerase-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Jasmonic Acid
Jasmonic acid (JA) is an organic compound found in several plants including jasmine. The molecule is a member of the jasmonate class of plant hormones. It is biosynthesized from linolenic acid by the octadecanoid pathway. It was first isolated in 1957 as the methyl ester of jasmonic acid by the Swiss chemist Édouard Demole and his colleagues. Biosynthesis Its biosynthesis starts from the fatty acid linolenic acid, which is oxygenated by lipoxygenase (13-LOX), forming a hydroperoxide. This peroxide then cyclizes in the presence of allene oxide synthase to form an allene oxide. The rearrangement of allene oxide to form 12-oxophytodienoic acid is catalyzed by the enzyme allene oxide cyclase. A series of β-oxidations results in 7-isojasmonic acid. In the absence of enzyme, this isojasmonic acid isomerizes to jasmonic acid. Function The major function of JA and its various metabolites is regulating plant responses to abiotic and biotic stresses as well as plant growth and de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
