Aqueous Diels-Alder Reactions of Cyclopentadicnc with Symmetric Diester of Fumarate or Maleate

Cis- or irans- dimethyl and diethyl ester of bicyclo[2,2,1]hept-5-ene-2,3-die(2 or 4) were used as pesticides 1-4 in the fourties and fifties of the century to prevent orkill mosquito, fly and flea. The of's-dimethyl ester Za was also added to cosmetics forthe same purpose 5. The diethyl and dipropyl esters (2b and Zc) could be used to makerubber and elastomers6'7. Besides, this kind of compounds are important intermediatesfor synthesis of some drugs.The Diels-Alder reaction of cyclopentadie…     

Synthesis of 2-Acyl-2H-1,2,3-diazaphospholes and Their Diels-Alder Reaction with Cyclopentadiene

2H-1,2,3-Diazaphospholes 3a-3h were prepared from various ketone acylhydrazones and phosphorus trichloride in the presence of triethylamine. Compounds 3 underwent feasible hetero-Diels-Alder reactions with cyclopentadiene to afford the respective anellated [1,2,3]diazaphospholes 4a--4d as well as 4a‘--4d‘ in moderate yields. The endo rule in the reaction was observed under kinetic control conditions.     

Diels-Alder Reactions of 6,9-Dipropyl-1, 4-Dioxaspiro[4.5]Deca-6, 8-Diene-2, 10-Dione with Substituted Alkenes. An Entry to Bicyclo[2.2.2]Oct-5-Ene-2, 3-Diones and 1, 3-Cyclohexadienes

The cycloadditions of the title compound, 1, a masked 3, 6-dipropyl-o-benzoquinone to various disubstituted (diethyl maleate, diethyl fumarate, trans- and cis-stilbene, and cycloheptene) and monosubstituted alkenes (methyl acrylate, methyl vinyl ketone, styrene, ethyl vinyl ether, and 1-hexene) have been studied; the yields of the Diels-Alder adducts, 2, are generally high (> 75%) except for stilbenes. These adducts are effectively transformed into the corresponding bicyclo[2.2.2]oct-5-ene-2, 3-diones, 3, whose stereochemistries are determined from the ring current effect of the respective quinoxalines, 4, on the chemical shifts of the vinyl and the methine protons and/or the lanthanide (Eu(fod)₃) induced shift on the pertinent protons of 3. It is interesting to note that the quinoxaline ring current makes the vinyl protons down-field shifted by 0.15–0.27 ppm whereas the methine protons (R³=H) syn to the quinoxaline moiety up-field shifted by 0.18–0.39 ppm as compared to the chemical shifts of the corresponding protons in 3. The transformations of α-diketones 3 into the corresponding 1, 3-cyclohexadienes, 5, by irradition with a Hanovia medium pressure lamp through a uranium glass filter are almost quantitative. The present study provides facile and effective methods for the preparation of bicyclo[2.2.2]oct-5-ene-2, 3-diones and 1, 3-cyclohexadienes from catechols via masked o-benzoquinones.     

外式双环[2.2.1]庚烷(庚-5-烯)-2,3-二甲酸酐膦二肽衍生物的合成

选择有机磷基团对斑蝥素的结构骨架进行修饰改造,以外式双环[2.2.1]庚-5-烯-2,3-二甲酸酐为原料,设计合成了一系列斑蝥素类似物。化合物的结构经1HNMR,MS及元素分析确证。     

Metathesis of spirocyclo[2.2.1]hept-2-ene-7,1'-cyclopropane

Metathesis of spirocyclo[2.2.1]hept-2-ene-7,1'-cyclopropane and its co-metathesis with norbornene and 5-decene on homogeneous and heterogeneous catalytic systems were carried out for the first time. The reactions were shown to proceed with retention of the spirosystem.Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 138–139, January, 1993.     

Diels-Alder reactions of masked o-benzoquinones with acrylonitrile

Regioselective Diels-Alder reactions of masked o-benzoquinones (MOBs) 2a-i derived from the corresponding 2-methoxyphenols 1a-i with acrylonitrile leading to highly functionalized bicyclo[2.2.2]octenone derivatives in high yields are described.     

Three-component synthesis of polysubstituted benzene derivatives via Diels-Alder reaction of cyclopentadienone acetal with alkyne

An efficient and regioselective synthesis of polysubstituted benzene derivatives was achieved via multicomponent reaction of a substituted cyclopropenone acetal and two alkyne molecules. The synthesis utilizes cyclopentadienone acetal as an intermediate and enables regioselective [2+2+2] assembly of the three-components into a benzene ring. A variety of polysubstituted benzene derivatives of synthetic and structural interest have been synthesized.     

The reaction of mercuric salts with dimethyl bicyclo[2.2.2]octa-2,5-diene-5,6-dicarboxylate

The regioselectivity and stereochemistry of the reaction of mercuric salts with dimethyl bicyclo[2.2.2.]octa-2,5-diene-5,6-dicarboxylate were studied in different solvents. The factors determining the reaction regioselectivity were considered.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1642–1645, September, 1993.     

2,3-二溴甲基喹喔啉与C60的Diels-Alder反应

Ｃ60 是富勒烯家族的一员[1] 。Ｃ60 分子的发现是Ｈ .Ｗ .Ｋｒｏｔｏ和Ｒ .Ｅ .Ｓｍａｌｌｅｙ等人于 1 985年 ,在氦气流中以激光蒸发石墨 ,从而获得以Ｃ60 为主的质谱图的 ,并在实验室制得了Ｃ60 分子[2 ] 。 1 990年德国科学家Ｋｒａｔｓｃｈｍｅｒ,Ｗ和美国科学家Ｈｕｆｆｍａｎ ,Ｄ .Ｒ .等用电弧法克量级制备Ｃ60 获得成功[3] 。从此 ,世界范围内掀起了一股Ｃ60 的研究热 ,对Ｃ60 进行各种化学修饰更是化学家的热门课题 ,经化学修饰的Ｃ60 衍生物具有潜在的应用前景。近几年 ,Ｃ60 化学反应的研究十分活跃 ,氧化反应、还原反应、聚合…     

Oxidative Diels-Alder reaction of 2, 5-dihydroxybenzoic acid with 1, 3-cyclopentadiene

The electrochemical oxidation of 2,5-dihydroxybenzoic acid (1) has been studied in the presence of 1,3-cyclopentadiene (2) as a diene in water/ethanol (40/60, v/v) mixture using cyclic voltammetry and controlled-potential coulometry. A plausible mechanism for the oxidation of 1 in the presence of 2 is presented. Compound 1 was converted into bis-adduct 5 via electrooxidation, Diels-Alder reaction of 2 to anodically generated 3,6-dioxocyclohexa-1,4-dienecarboxylic acid (1ox), decarboxylation reaction, electrooxidation and Diels-Alder reaction. The electrochemical synthesis of 5 was performed in a onepot reaction, without toxic reagents, at a carbon electrode in a simple cell using an environmentally friendly method.     

Facile and Clean Synthesis of Furopyridine Derivatives via Three-Component Reaction in Aqueous Media Without Catalyst

A series of furo[2′,1′:5,6]pyrido[2,3-d]pyrimidine derivatives were synthesized via the three-component reaction of an aldehyde, tetronic acid, and 6-amino-1,3-dimethyl-pyrimidine-2,4-dione in aqueous media without the use of catalyst. This protocol has the advantages of better yields, less cost, reduced environmental impact, and convenient procedure.     

(S)-1,1-二苯基-2-吡咯啶甲醇催化蒽酮与马来酰亚胺的不对称Diels-Alder反应

研究了(S)-1,1-二苯基-2-吡咯啶甲醇催化蒽酮与马来酰亚胺的不对称D iels-A lder反应,考察了蒽酮与不同N-取代马来酰亚胺的反应。结果表明,在最佳反应条件下化学产率97%,对映选择性44%。     

Synthesis of 5-vinyl-2-norbornene through Diels-Alder reaction of cyclopentadiene with 1, 3-butadiene in supercritical carbon dioxide

An efficient method for the synthesis of 5-vinyl-2-norbornene from cyclopentadiene and 1,3-butadiene was developed.The Diels-Alder reaction of cyclopentadiene with 1,3-butadiene proceeded smoothly in supercritical carbon dioxide in the absence of any polymerization inhibitor to produce the corresponding 5-vinyl-2-norbornene in satisfactory yield with high selectivity.     

Stereoselectivity of the reaction of mercuric acetate with dimethyl bicyclo[2.2.2]oct-2-en-5,6-cis-endo-dicarboxylate

The stereoselelectivity of the reaction of mercuric acetate with dimethyl bicyclo[2.2.2]oct-2-en-5, 6-cis-endo-carboxylate in acetic acid was studied. One of the reaction products is formed when the reagent attacks the double bond from the sterically less accessible side. The nature of the orientation effect of the carboxylate groups is discussed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1646–1648, September, 1993.     

Tandem intramolecular Diels–Alder/retro-Diels–Alder cycloaddition of 2H-chromen-2-one as dienes with the expulsion of CO_2

To study the intramolecular Diels-Alder cycloadditon of 2H-chromen-2-one as a diene, a series of chiral N-allyl-N-benzylamides that contain a 2H-chromen-2-one moiety were designed for the synthesis of benzo[f]isoindol-1-ones via an intramolecular Diels-Alder and a subsequent retro-Diels-Alder cycloaddition with the expulsion of CO₂. Both the yield (80%-89%) and absolute stereocontrol of the tandem reaction were high when an electron-withdrawing group was attached to the dienophile. The double bond in the styrene substructure remained in the products could be further derivatized by dihydroxylation.     

抗肿瘤活性化合物5-烯去甲基斑蟊酸与氨基酸三元配合物的研究及其血浆模型的模拟计算

用pH电位法测定了在生理条件下(37℃,I=0.15mol/LNaCl)₇-氧杂双环-[2,2,1]庚-5-烯-2,3-二羧酸(OHDA)与各种典型氮基酸和锌、铜生成三元混配配合物的生成常数.模拟计算表明,作为药物配体的OHDA确可影响体内复杂的低分子量金属配合物的平衡,并且扰乱体内锌的分布,改变各种含锌酶的活性和功能.     

两个环己烷螺含氮杂环化合物的合成和晶体结构

环己酮与硫代碳酰肼在不同介质中的反应，合成出两个不同的环己烷螺含氮杂环化合物。经Ｘ－射线结构分析确定它们分别为１，２，４，５－四氮螺［５，５］十一烷－３－硫酮，Ｃ＿７Ｈ＿（１４）Ｎ＿４Ｓ（Ⅰ）和１，２，４，－三氮螺［４，５］癸－１－烯－４－氨基－３－硫酮。Ｃ＿７Ｈ＿（１２）Ｎ＿４Ｓ＿ｘ（Ｓ＿ｘ＝０．８Ｓ＋０．２Ｏ）（Ⅱ）。晶体学参数分别为（Ⅰ）：Ｐ２＿１／ｃ，ａ＝１２．０２６（４），ｂ＝２６．８１７（６），ｃ＝１２．０４２（３），β＝１１５．９４（２）°，Ｚ＝４，Ｖ＝９３３．４（１０），Ｍ＿ｒ＝１８６．２８；（Ⅱ）：Ｐ２＿１／ｍ，ａ＝６．５９５（７），ｂ＝６．８１７（６），ｃ＝１０．５７２（６），β＝１０６．３（１）°，Ｖ＝４５６（１），Ｚ＝２，Ｍ＿ｒ＝１８１．０５。最终一致因子分别为Ｒ＝０．０５４，Ｒ＿ｗ＝０．０６５和Ｒ＝０．０８９，Ｒ＿ｗ＝０．０９６。两个化合物中，环己烷都为椅式构型，它与其螺联的６员氮杂环，５员氮杂环的最小二乘平面间的夹角分别为６８．９４和９０°。并对合成反应途径作了初步讨论。     

A method for synthesis of bicyclo[3.3.0]oct-1-en-3-ones from cyclobutanones with one-carbon ring expansion and its application to a formal synthesis of racemic 1-desoxyhypnophilin

A method for synthesis of 2-cyanobicyclo[3.3.0]oct-1-en-3-ones and 2-substituted bicyclo[3.3.0]oct-1-en-3-ones was developed by assembly of three components, cyclobutanones, chloromethyl p-tolyl sulfoxide, and nitriles, with one-carbon ring expansion of the cyclobutane ring. As an application of this method, a formal synthesis of 1-desoxyhypnophilin in racemic form was performed starting from 3,3-di(phenylthiomethyl)cyclobutanone.     

Reactions of 4-Chloro-3-formylcoumarin with Arylhydrazines

The interaction of 3-formyl-4-coumarin with arylhydrazine hydrochlorides in the presence of sodium acetate gave the corresponding 3-arylhydrazonomethyl-4-chlorocoumarin, and with phenylhydrazine, 4-bromo- and 4-chlorophenylhydrazine hydrochlorides in the presence of two equivalents of triethylamine gave either 1-aryl- or 2-aryl[1]benzopyrano[4,3-c]pyrazol-4-ones depending on the reaction conditions. In reactions of 4-chloro-3-formylcoumarin with 2,4-dichloro-, 2,4-difluoro-, 2-hydroycarbonyl-, 4-nitro- and 3,5-di(trifluoromethyl)phenylhydrazine, 2-pyridyl- and 2-quinoxalylhydrazine in the presence of excess of triethylamine the 2-aryl[1]benzopyrano[4,3-c]pyrazol-4(2H)-ones were obtained exclusively. The structures of 1-phenyl- and 2-(2-pyridyl)[1]benzopyrano[4,3-c]pyrazolo-4(1H)ones were confirmed by X-ray crystallography. A simple method is proposed to distinguish between 1- and 2-substituted [1]benzopyrano[4,3-c]pyrazolo-4-ones on the basis of the ¹H NMR chemical shifts of the C(3)-H proton in two solvents - DMSO-d₆ and CDCl₃.     

An efficient synthesis of novel pyridothieno-fused thiazolo[3,2-a]pyrimidinones via Pictet–Spengler reaction

An efficient method for the synthesis of novel pyrido[3',2':4',5']thieno[3',2':2,3]pyrido [4,5:d][1,3]thiazolo[3,2-a]pyrimidine-4-one derivatives (5) has been developed using a Pictet-Spengler reaction between 2-(3-aminothieno[2,3-b]pyridin-2-yl)thiazolo[3,2-a] pyrimidin-5-one (3), which could be obtained from the condensation of 7-(chloromethyl)-5H-thiazolo[3,2-a]pyrimidin-5-one (1) with 3-cyanopyridine-2-thione (2) via Thorpe-Ziegler isomerization, and aromatic aldehydes under NH₂SO₃H as catalysis in good yields.