共查询到19条相似文献,搜索用时 78 毫秒
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从α-蒎烯出发,通过臭氧化,硼氢化钠还原剂随后用硫酸处理的一锅法,合成了一个新的萜类四氢呋喃衍生物-2,2-二甲基-3-(反-2-丁烯基)-四氢呋喃3,总收率55.6%,将α-蒎烯(78,51mmol)的150mL异丙醇溶液冷至-2℃,鼓泡通入含5~6%臭氧的氧气至过量的臭氧从溶液中逸出时止,再通N210min。于0℃将上述溶液滴加至100mL含硼氢化钠(2.54g,65mmol)和氢氧化钠(0. 相似文献
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α-蒎烯在常温、常压、液相条件下,在光敏剂溶剂中受紫外光照射,开环异构为罗勒烯.在这个光敏异构化反应过程中获得单一的产物—顺式和反式罗勒烯,经分馏后产物纯度达99.3%(折光率n_D~(25)=1.4870,比重D~(25)=0.7946). 相似文献
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β-蒎烯是一个重要的有机合成原料,但我国松节油中的β-蒎烯含量甚少,主要为α-蒎烯·将α-蒎烯异构化成为β-衍生物已有许多报道。本文将三乙基硼氨合物或三乙基苄基铵合硼烷使之与α-蒎烯反应成二(3-蒎烷基)硼烷,再经热异构重排成二(10-蒎烷基)硼烷,最后与双戊烯进行置换反应,顺利地制得了β-蒎烯。与Brown的方法相比,本法简便、安全,并且用我国合成樟脑生产中的副产物双戊烯代替了十二烯-(1)。 相似文献
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立体选择合成是当今有机合成中一个较新的,极其活跃的研究领域。而利用手性模板进行不对称诱导反应,则是立体选择合成的一种重要方法。近年来,国外报道了许多利用手性模板获得高光学纯度的氨基酸的事例。1981年,Schoellkopf 等用环烯状的双内酰亚胺作手性模板获得了高光学纯度的α-氨基酸。1986年,Williams 用亲电性的甘氨酸内酯作为手性模板进行不对称诱导反应,得到了光学纯度96.5~99.5%的一系列α-取代氨基酸。因此,选择一个好的手性模板是获得高光学纯度产物的关键。较理想的手性模板必须满足以下条 相似文献
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β-蒎烯氧化反应研究进展 总被引:2,自引:0,他引:2
综述了松节油中β-蒎烯的氧化反应的研究进展。目前研究的氧化方法有高锰酸钾氧化、环氧化、四醋酸铅氧化、臭氧氧化、光敏氧化和二氧化硒氧化等。通过各种氧化方法,β-蒎烯可用于合成诺蒎酸、诺蒎酮、2,l0-环氧蒎烷、水芹醛、紫苏醇、紫苏醛、紫苏葶、桃金娘烯醇等。 相似文献
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松节油及α-蒎烯和β-蒎烯的臭氧化反应 总被引:2,自引:0,他引:2
松节油的主要成分是 α-蒎烯和 β-蒎烯 ,经臭氧化反应后分别生成蒎酮醛和诺蒎酮的前提化合物 [1] ,它们是合成珍贵香料鸢尾酮和 4-异丙基环己酮衍生物等香料的中间体 .α-蒎烯和 β-蒎烯在气相中的臭氧化反应动力学 [2 ]和 β-蒎烯的液相臭氧化反应 [3]已有研究 ,但 α-蒎烯和 β-蒎烯混合物以及松节油在溶液中的臭氧化反应选择性未受到关注 ,影响了松节油的直接臭氧化深加工利用 .采用松节油直接臭氧化是降低由 α-蒎烯合成鸢尾酮成本的重要途径 .本文通过 α-蒎烯和 β-蒎烯二元混合物及松节油在乙醇中的臭氧化反应的实时反应物浓度分析 … 相似文献
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西松烷型二萜天然产物全合成最新进展 总被引:3,自引:0,他引:3
西松烷型二萜类化合物是近年来相继发现的一大类结构新颖,特殊且具有重要生物活性的天然产物。本文将扼要地论述近几年此类化合物的全合成最新研究进展,其中包括我国近年来的研究成果。 相似文献
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Progress in the chemistry of the cycloartanes 总被引:2,自引:0,他引:2
The review, which considers advances in the chemistry of the cycloartanes, covers literature devoted to compounds of plants of the genusAstragalus and other publications appearing in the period from 1984 to 1987 and, in part, 1988.Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 156–175, March–April, 1989. 相似文献
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This review deals with the synthesis and reactions of 5-acetylthiazoles. Some of these reactions have been used successfully for the production of biologically important compounds. The main purpose of this review is to present a survey of the literature on the chemistry of 5-acetylthiazoles and to provide useful and up-to-date information on their applications because these compounds have not been previously reviewed. 相似文献
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Antoni S. Gozdz 《先进技术聚合物》1994,5(1):70-78
Recent developments in the chemistry of organosilicon polymers for use as oxygen plasma-resistant imaging materials in microlithography are reviewed. Various classes of resists, grouped according to molecular structure, are described with special emphasis on properties critical in microlithographic applications. In addition, several silylation schemes involving selective silylation of a non-silicon-containing resist material following patternwise exposure to actinic radiation are also described. 相似文献
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Khakina EA Troyanov SI Peregudov AS Soulimenkov IV Polyakova NV Troshin PA 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(43):12947-12955
We report the first reaction of trannulenes involving their thermal isomerization to a new class of compounds termed "triumphenes". The thermodynamically controlled conversion of trannulenes into triumphenes is accompanied by an unprecedented migration of three organic addends from one hemisphere of the fullerene cage to another. The reaction products, bearing aliphatic substituents, might find applications in materials science as strong electron acceptors due to the presence of fifteen electron-withdrawing fluorine atoms in their molecular framework. It was revealed that the isomerization of trannulenes can be affected by the presence of unsaturated compounds in the reaction mixture. Heating of trannulenes C(60)F(15)R(3) with C(60), C(70), anthracene, or pentacene at reflux in 1,2-dichlorobenzene yields fluorinated derivatives C(60)F(14)R(2)A, which possess a fused cyclic addend A. The products of this reaction have "triumphene-type" addition patterns and seem to be formed through an unprecedented sequence of elimination, addition, and isomerization steps. The molecular structure of a representative triumphene was proven unambiguously by X-ray single-crystal diffraction analysis and by NMR spectroscopy. The reactions revealed here open up numerous opportunities for chemical derivatization of fluorinated fullerenes. This method promises to provide a new path towards valuable photoactive materials and a new generation of fullerene-based compounds that are suitable for biomedical applications. 相似文献
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Venkataramana Imandi Sooraj Kunnikuruvan Dr. Nisanth N. Nair 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(15):4724-4731
The complete reaction mechanism and kinetics of the Wacker oxidation of ethene in water under low [Cl?], [PdII], and [CuII] conditions are investigated in this work by using ab initio molecular dynamics. These extensive simulations shed light on the molecular details of the associated individual steps, along two different reaction routes, starting from a series of ligand‐exchange processes in the catalyst precursor PdCl42? to the final aldehyde‐formation step and the reduction of PdII. Herein, we report that hydroxylpalladation is not the rate‐determining step and is, in fact, in equilibrium. The newly proposed rate‐determining step involves isomerization and follows the hydroxypalladation step. The mechanism proposed herein is shown to be in excellent agreement with the experimentally observed rate law and rate. Moreover, this mechanism is in consensus with the observed kinetic isotope effects. This report further confirms the outer‐sphere (anti) hydroxypalladation mechanism. Our calculations also ratify that the final product formation proceeds through a reductive elimination, assisted by solvent molecules, rather than through β‐hydride elimination. 相似文献
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Ultrasound in analytical chemistry 总被引:1,自引:0,他引:1
Ultrasound is a type of energy which can help analytical chemists in almost all their laboratory tasks, from cleaning to detection.
A generic view of the different steps which can be assisted by ultrasound is given here. These steps include preliminary operations
usually not considered in most analytical methods (e.g. cleaning, degassing, and atomization), sample preparation being the
main area of application. In sample preparation ultrasound is used to assist solid-sample treatment (e.g. digestion, leaching,
slurry formation) and liquid-sample preparation (e.g. liquid–liquid extraction, emulsification, homogenization) or to promote
heterogeneous sample treatment (e.g. filtration, aggregation, dissolution of solids, crystallization, precipitation, defoaming,
degassing). Detection techniques based on use of ultrasonic radiation, the principles on which they are based, responses,
and the quantities measured are also discussed. 相似文献