Diels-Alder Reaction of Hedychenone and Maleic Anhydride

SeveraIditerPenoidswithantitum0ractivity,includinghedychenonel,afiJranoidcompound,werepreviouslyis0latedfr0mHetychiumgenus'.Inattemptt00btains0mediterPen0idderivativeswithhigherantitum0ractivity,Diels-Alderreactionoflwithmaleicacidanhydride2wasintr0ducedt0getsomeanalogues0fcantharidin3,anantitUm0rmedicineinclinicaluse.Reaction0flandexcessive2at0Cinchloroformgavetw0thermodynamicaIlydominatedexoadducts4and5,togetherwithamixtureoftWokinetical1ydominatedendoadducts6and7.Whenthereacti0nwasc0ndu…     

Synthesis and Properties of Nonionic Surfactants from Rosin-Imides Maleic Anhydride Adduct

Ester-adduct derivatives of rosin were synthesized by reacting rosin with polyethylene glycol 600 (PEG 600) or 2000 (PEG2000) and maleic anhydride (MA) at elevated temperature. These derivatives were evaluated for acid number, FTIR spectroscopy, molecular weight (Mw), and polydispersity. The derivatives were soluble in organic solvents; aqueous solubility was pH dependent. Rosin-imides were synthesized from a rosin ester-maleic anhydride adducts. It was condensed with diaminobutane or triethylene tetramine to obtain rosinimides. This imide was etherified by reaction with PEG in the presence of β,β′-dichlorodiethyl ether as a linking agent and NaOH as a catalyst. The surface properties of the prepared surfactants were determined by measuring the surface tension at different temperatures. The surface tension, critical micelle concentration and surface activities were determined at different temperatures. Surface parameters such as surface excess concentration (Γmax), the area per molecule at interface (Amin), and the effectiveness of surface tension reduction (πCMC) were determined from the adsorption isotherms of the prepared surfactants. Some thermodynamic data for the adsorption process were calculated and are discussed.     

Orthobromodiphenylmethane Derivatives as Starting Materials for the Total Synthesis of Anthraquinones

In this communication we describe the synthesis of four simple anthraquinones by a five-step sequence, using easily available bromobenzaldehydes and phenyllithium derivatives as starting materials.     

Study of Adducts in the Photometric Determination of Maleic Anhydride by Its Reaction with 2-Methylimidazole

The interaction of maleic anhydride with 2-methylimidazole in different solvents and without solvents was studied using electronic, IR, and ¹H NMR spectrometry; differential scanning calorimetry; and potentiometric titration. On the basis of experimental data and quantum-chemical calculations, it was demonstrated that molecular complexes can be formed as intermediates in the chain of consecutive reactions. It was found that, depending on the nature of anhydride, complex formation can be absent (in the case of phthalic anhydride). Because of the formation of the molecular complex between maleic anhydride and 2-methylimidazole, the nucleophilic addition of the latter at the double bond of anhydride yielding amide of the succinic acid derivative is possible.     

氨基酸5-氟尿嘧啶酯类衍生物的合成及其抗肿瘤活性研究

以N-保护的氨基酸钾盐与1-(ω-溴丙基)-5-氟尿嘧啶和1-(ω-溴丁基)-5-氟尿嘧啶反应,制备了18种氨基酸的ω-(N¹-5-氟尿嘧啶基)-丙醇酯和丁醇酯的盐酸盐,并确定了它们的结构。动物试验的初步结果表明,酪氨酸、苯丙氨酸的3-(N¹-5-氟尿嘧啶基)-丙醇酯盐酸盐对小鼠艾氏腹水癌的抑制率分别为88.1%和86.7%。     

α-蒎烯与马来酸酐异构/Diels-Alder反应的进展

本文就近30年来α-蒎烯的异构及α-蒎烯和马来酸酐异构／Diels-Alder反应这两类反应进行了综述。重点考查了反应所用的催化剂、反应条件并进行比较，指出加强这方面的基础研究对充分利用我国松脂资源十分有利，其发展前景不可低估。     

氨基硅烷/马来酸酐接枝聚丙烯界面化学反应的研究

利用溶剂萃取与红外光谱（IR）、光电子能谱（XPS）技术研究了化学键接在玻璃纤维表面的硅烷偶联剂与接枝聚丙烯间的界面化学反应。结果表明：溶剂萃取可以除去玻璃纤维/树脂界面区物理结合的聚合物基体,减少基体信号的影响,在此基础上,利用IR、XPS可以直接证明氨基硅烷（APS）与马来酸酐接枝聚丙烯（MA-g-PP）间发生了界面化学反应,生成了含酰胺基的反应产物。进一步对不同化学状态的N1s的XPS定量分析发现,尽管APS在玻纤表面以开环直链和以氢键结合的环状两种结构形式存在,但在界面上主要是无环开链结构中的氨基与酸酐发生反应。     

Synthesis of Novel 1,4-Benzoxazine-2,3-Dicarboximides from Maleic Anhydride and Substituted Aromatic Amines

A series of novel 1,4-benzoxazine-2,3-dicarboximides starting from maleic anhydride and substituted aromatic amines were synthesized.     

Synthesis and Cytotoxic Activity of 1,3,5-Triazinane Derivatives Based on Primary Amines and Amino Acids Esters

Russian Journal of General Chemistry - A series of 1,3,5-triazinane derivatives was synthesized and their cytotoxic activity was studied in vitro on normal cell line (HEK293) and tumor cell lines...     

苯乙烯/马来酸酐共聚物智能水凝胶的制备与性能

合成了苯乙烯/马来酸酐共聚物接枝聚乙二醇400(PEG400)水凝胶.研究了环境pH、温度、离子强度对该凝胶溶涨性能的影响,并对凝胶的动态溶涨行为进行了分析.结果显示该水凝胶对环境pH、温度、离子强度等变化均作出体积相转变响应,表现出了智能高分子凝胶的特性.     

Spontaneous Aromatization of Diels-Alder Adducts in the Reaction of Alkatrienyl Phosphonates with Alkyl Esters of Acetylencarboxylic Acids

Abstract

The subject of this study was the Diels-Alder reaction involving dialkyl (3-methylpenta-1,2,4-trienyl)phosphonates1a-d, dialkyl(5-methyl-hexa-1,3,4-trienyl)phosphonates 2a-b, and dienophiles (esters of acetylencarboxylic acids) 3a-c, at 65–90°C, in chloroform or with no solvent. The reaction between 1a-d and 3a-b led to the benzyl phosphonates 4a-h, while with 3c it proceeds to a mixture of 5a-d (90%) and 6a-d (10%), which are dialkyl esters of the 3-carboalkoxy(or 2-carboalkoxy)-6-methyl-benzyl phosphonic acid. The intermediate Diels-Alder adducts (A) are not even spectroscopically observable, i.e. in the course of the reaction a 1,5-sigmatropic isomerization occurs, accompanied by aromatization of (A). The isomerization is spontaneous: at ambient temperature 1a-d and 3a-b react slowly and form aromatic compounds:     

Microwave Assisted Synthesis of Diosgenin Esters of Maleic and Itaconic Acids

Diosgenin monomaleate and diosgenin monoitaconate were prepared by the esterification of diosgenin with maleic and itaconic anhydride, respectively, in toluene using p-toluenesulphonic acid as catalyst. A domestic microwave oven was modified and used for the synthesis of both products. The reaction time for consuming all the diosgenin according to thin-layer chromatography (TLC) was reduced by around 90% in the synthesis of monomaleate of diosgenin as well as in the synthesis of monoitaconate of diosgenin in comparison with conventional heating, whereas the monomaleate of diosgenin yield increased from 43 to 80–85% and the monoitaconate of diosgenin yield from 34 to 95% under the same experimental conditions. It was easier to purify the diosgenin monoitaconate than the diosgenin monomaleate. Both products were characterized by NMR and FTIR spectroscopy.     

Asymmetric Synthesis of Secondary and Tertiary Boronic Esters

Non‐racemic chiral boronic esters are recognised as immensely valuable building blocks in modern organic synthesis. Their stereospecific transformation into a variety of functional groups—from amines and halides to arenes and alkynes—along with their air and moisture stability, has established them as an important target for asymmetric synthesis. Efforts towards the stereoselective synthesis of secondary and tertiary alkyl boronic esters have spanned over five decades and are underpinned by a wealth of reactivity platforms, drawing on the unique and varied reactivity of boron. This Review summarizes strategies for the asymmetric synthesis of alkyl boronic esters, from the seminal hydroboration methods of H. C. Brown to the current state of the art.     

Highly Enantioselective Methanolysis of Meso‐Cyclic Anhydride Mediated by Bifunctional Thiourea Cinchona Alkaloid Derivatives: Access to Asymmetric Total Synthesis of (+)‐Biotin

An enantioselective asymmetric total synthesis of (+)?biotin ( 1 ) via the Hoffmann–Roche lactone–thiolactone strategy has been accomplished from commercially available cis‐1,3‐dibenzyl‐2‐imidazolidone‐4,5‐dicarboxylic acid ( 2 ). Strategic transformations include a cinchona alkaloid‐based bifunctional thiourea mediated methanolytic desymmetrization of prochiral cyclic anhydride 3 to produce the enantiomerically enriched precursor of Roche lactone 5 and an improved introduction of the 4‐carboxybutyl side chain at C‐4 position of Roche thiolactone 6 via Grignard reaction.     

A One-Pot Synthesis of trans-N-Alkylaziridine-2-carboxylates from Amino Alcohol Esters

A series of new trans-N-alkylaziridine-2-carboxylates 3 was conveniently synthesized in a one-pot reaction by treatment of 1,2-amino alcohol mono and diesters 1 with methanesulfonyl chloride in the presence of (iPr)₂NEt. The products were obtained in good to excellent yields with high trans-selectivity.

单氯代苯酐及其衍生物的合成方法研究进展

讨论了3(4)-氯代苯酐的主要合成方法以及它们的主要衍生物联苯二酐和二苯醚二酐等的合成方法和主要用途. 综合比较了各种合成方法的利弊, 并分析了这些化合物的国内外研究现状和发展趋势.