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Pinacolone
Pinacolone (3,3-dimethyl-2-butanone) is an important ketone in organic chemistry. It is a colorless liquid with a slight peppermint or camphor odor. It is a precursor to triazolylpinacolone in the synthesis of the fungicide triadimefon and in synthesis of the herbicide metribuzin. The molecule is an unsymmetrical ketone. The α-methyl group can participate in condensation reactions. The carbonyl group can undergo the usual reactions (hydrogenation, reductive amination, etc.). It is a Schedule 3 compound under the Chemical Weapons Convention 1993, due to being related to pinacolyl alcohol, which is used in the production of soman. It is also a controlled export in Australia Group member states. Preparation Most famously, at least in the classroom, pinacolone arises by the pinacol rearrangement, which occurs by protonation of pinacol (2,3-dimethylbutane-2,3-diol). : Industrially pinacolone is made by the hydrolysis of 4,4,5-trimethyl-1,3- dioxane, which is the product of i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinacol Rearrangement
The pinacol–pinacolone rearrangement is a method for converting a diol, 1,2-diol to a carbonyl compound in organic chemistry. The 1,2-rearrangement takes place under acidic conditions. The name of the rearrangement reaction comes from the rearrangement of pinacol to pinacolone. : This reaction was first described by Wilhelm Rudolph Fittig (of Fittig reaction fame) in 1860. Mechanism In the course of this organic reaction, protonation of one of the –OH groups occurs and a carbocation is formed. If the –OH groups are not alike (i.e. the pinacol is asymmetrical), then the one which creates a more stable carbocation participates in the reaction. Subsequently, an alkyl group from the adjacent carbon migrates to the carbocation center. The driving force for this rearrangement step is believed to be the relative stability of the resultant oxonium ion. Although the initial carbocation is already tertiary, the oxygen can stabilize the positive charge much more favorably due to the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pivalic Acid
Pivalic acid is a carboxylic acid with a molecular formula of (CH3)3CCO2H. This colourless, odoriferous organic compound is solid at room temperature. Two abbreviations for pivalic acid are ''t''-BuC(O)OH and PivOH. The pivalyl or pivaloyl group is abbreviated ''t''-BuC(O). Pivalic acid is an isomer of valeric acid, the other two isomers of it are 2-methylbutanoic acid and 3-methylbutanoic acid. Preparation Pivalic acid is prepared on a commercial scale by hydrocarboxylation of isobutene via the Koch reaction: :(CH3)2C=CH2 + CO + H2O → (CH3)3CCO2H Such reactions require an acid catalyst such as hydrogen fluoride. ''tert''-Butyl alcohol and isobutyl alcohol can also be used in place of isobutene. Globally, several million kilograms are produced annually. Pivalic acid is also economically recovered as a byproduct from the production of semisynthetic penicillins like ampicillin and amoxycillin. It was originally prepared by the oxidation of pinacolone with chromic acid: : A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paclobutrazol
Paclobutrazol (PBZ) is the International Organization for Standardization, ISO trivial name, common name for an organic compound that is used as a Plant growth regulator, plant growth retardant and triazole fungicide. It is a known receptor antagonist, antagonist of the plant hormone gibberellin, acting by inhibiting gibberellin biosynthesis, reducing Internode (botany), internodal growth to give stouter stems, increasing root growth, causing early fruitset and increasing seedset in plants such as tomato and Capsicum, pepper. PBZ has also been shown to reduce frost sensitivity in plants. Moreover, paclobutrazol can be used as a chemical approach for reducing the risk of lodging (agriculture), lodging in cereal crops. PBZ has been used by arborists to reduce shoot growth and shown to have additional positive effects on trees and shrubs. Among those are improved resistance to drought stress, darker green leaves, higher resistance against fungi and bacteria, and enhanced development of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinacol
Pinacol is a branched alcohol which finds use in organic syntheses. It is a diol that has hydroxyl groups on vicinal carbon atoms. A white solid that melts just above room temperature, pinacol is notable for undergoing the pinacol rearrangement in the presence of acid and for being the namesake of the pinacol coupling reaction. Preparation It may be produced by the pinacol coupling reaction from acetone: Reactions As a vicinal diol, it can rearrange to pinacolone by the pinacol rearrangement, e.g., by heating with sulfuric acid: Pinacol can be used with borane and boron trichloride to produce useful synthetic intermediates such as pinacolborane, bis(pinacolato)diboron,{{OrgSynth , collvol = 10 , collvolpages = 115 , year = 2004 , prep = v77p0176 , title = Bis(pinacolato)diboron , author1 = Tatsuo Ishiyama, author2= Miki Murata, author3=Taka-aki Ahiko, author4-link= Norio Miyaura, author4=Norio Miyaura and pinacolchloroborane. See also * Pinacol coupling reaction * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bisphenol A
Bisphenol A (BPA) is a chemical compound primarily used in the manufacturing of various plastics. It is a colourless solid which is Solubility, soluble in most common organic solvents, but has very poor solubility in water. BPA is produced on an industrial scale by the condensation reaction of phenol and acetone. Global production in 2022 was estimated to be in the region of 10 million tonnes. BPA's largest single application is as a co-monomer in the production of polycarbonates, which accounts for 65–70% of all BPA production. The manufacturing of epoxy resins and vinyl ester resins account for 25–30% of BPA use. The remaining 5% is used as a major component of several high-performance plastics, and as a minor additive in polyvinyl chloride (PVC), polyurethane, thermal paper, and several other materials. It is not a plasticizer, although it is often wrongly labelled as such. The health effects of BPA have been the subject of prolonged public and scientific debate. BPA is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diethylstilbestrol
Diethylstilbestrol (DES), also known as stilbestrol or stilboestrol, is a nonsteroidal estrogen medication, which is presently rarely used. In the past, it was widely used for a variety of indications, including pregnancy support for those with a history of recurrent miscarriage, hormone therapy for menopausal symptoms and estrogen deficiency, treatment of prostate cancer and breast cancer, and other uses. By 2007, it was only used in the treatment of prostate cancer and breast cancer. In 2011, Hoover and colleagues reported adverse reproductive health outcomes linked to DES including infertility, miscarriage, ectopic pregnancy, preeclampsia, preterm birth, stillbirth, infant death, menopause prior to age 45, breast cancer, cervical cancer, and vaginal cancer. While most commonly taken by mouth, DES was available for use by other routes as well, for instance, vaginal, topical, and by injection. DES is an estrogen, or an agonist of the estrogen receptors, the biologic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triadimefon
Triadimefon is a fungicide Fungicides are pesticides used to kill parasitic fungi or their spores. Fungi can cause serious damage in agriculture, resulting in losses of yield and quality. Fungicides are used both in agriculture and to fight fungal infections in animals, ... used in agriculture to control various fungal diseases. As a seed treatment, it is used on barley, corn, cotton, oats, rye, sorghum, and wheat. In fruit it is used on pineapple and banana. Non-food uses include pine seedlings, Christmas trees, turf, ornamental plants, and landscaping. References Aromatase inhibitors Fungicides Triazoles 4-Chlorophenyl compounds {{Carbohydrate-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
