A series of mono and diesters of itaconic acid: Synthesis and structural determination

Summary A series of mono and diesters of itaconic acid containing alkoxy and sulfide side chains of variable lengths has been synthesized. Their structures have been established on the basis of their spectral data.

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Eine Serie von Mono- und Diestern von Itaconsäure: Synthese und Strukturbestimmung

Zusammenfassung Es wurde eine Serie von Mono- und Diestern von Itaconsäure mit Alkoxy- und Sulfidseitenketten variabler Länge synthetisiert. Die Strukturaufklärung erfolgte mittels spektroskopischer Daten.

     

芳香甲（乙）酯）铵盐的酰胺化与酰亚胺化

用热分析方法得出,由芳香酸甲酯或乙酯与4,4’-二氨基二苯甲烷制备的铵盐的酰胺化,酰亚胺化反应,较芳香酸的铵盐更易进行,反应温度和表观活化能均比四酸铵盐时低。由铵盐生成的聚酰亚胺具有很好的热氧化稳定性。     

食品中氯丙醇酯和缩水甘油酯污染状况及检测技术进展

氯丙醇酯类和缩水甘油酯类污染物对人体具有潜在的危害,目前已被发现普遍存在于精炼植物油、含油脂性食品、动物乳汁及母乳中,其中精炼植物油尤其是精炼棕榈油中的污染水平较高。食品中氯丙醇酯类和缩水甘油酯类污染问题已引起业界的广泛关注,针对该问题的相关研究正在不断深入,但仍有很多问题亟需解决。本文对食品中氯丙醇酯类和缩水甘油酯类来源、形成机理和毒性情况进行了综述,详细地介绍了国内外对食品中氯丙醇酯和缩水甘油酯有关限量规定和检测方法的研究现状。     

Synthesis of a (β-acetamido-α-acetoxyethyl)boronic ester via azido boronic esters

(Azidomethyl)boronic esters of 1,2-dicyclohexyl-1,2-ethanediol (“DICHED”) and pinanediol have been prepared from the corresponding (bromomethyl)boronic esters. Conversion to (2-azido-1-chloro- or bromoethyl)boronic esters by reaction with a (dihalomethyl)lithium followed. Attempted displacement of halide from DICHED (2-azido-1-haloethyl)boronates with alkoxides failed. Reaction of either pinanediol or DICHED (2-azido-1-chloromethyl)boronate with sodium acetate in acetic acid yielded the 1-acetoxy derivative as a ∼1:1 mixture of diastereomers, indicating probable involvement of an α-boryl carbocation intermediate. Hydrogenation of the pinanediol azido boronic ester over platinum in a solution of hydrogen chloride in dioxane was accompanied by deacetylation to form the impure (2-amino-1-hydroxyethyl)boronic ester hydrochloride. Attempted purification of this material resulted in deboronation to ethanolamine. Acetylation yielded pinanediol (2-acetamido-1-acetoxyethyl)boronate.     

含羟基芳基或氨基芳基的磷酰胺酯衍生物的合成

采用均相反应的方法合成了6个含羟基芳基或氨基芳基的磷酰胺酯衍生物:[(ClCH_2CH_2)_2NP(O)(OPh)(XArY)](X:O,NH;Y:m或p-OH或NH_2).用元素分析、红外光谱、氢核磁共振谱及质谱证实了它们的组成及结构.     

O,O′-二(2-氯乙基)-O″-[2-二(2-氯乙氧基)磷酰丙基]磷酸酯的合成

报道了以三氯化磷、乙二醇、环氧乙烷、丙酮和氯气等原料合成新型阻燃剂O,O′-二(2-氯乙基)-O″-[2-二(2-氯乙氧基)磷酰丙基]磷酸酯的方法.探讨了反应温度、催化剂以及反应时间等条件对各步反应的影响,产品总收率92%以上.采用元素分析、红外光谱和核磁共振等表征了合成化合物的结构.     

酶促合成全氟辛酸半乳糖脂

首次报道了酶促合成含氟糖脂。在IM-60脂肪酶催化下以85%产率得到了全氟辛酸半乳糖脂。     

双吡唑酮羧酸酯螯合剂的合成

1909年,Johannes 用丁、戊、已二酰丙二酸二乙酯与苯肼反应合成了相应的双吡唑酮羧酸酯(3)(n=2,3,4)。近年来,吡唑酮类化合物在金属离了的分析和分离工作中得到了广泛的应用。本文报道用类似于 Johannes 的方法,由     

Facile oxidative conversion of alcohols to esters using molecular iodine

A simple, efficient, and high-yield procedure for the oxidative conversion of alcohols to various types of esters and ketones, with molecular iodine and potassium carbonate was successfully carried out.     

Potassium Fluoride on Alumina—A New Reagent for Selective-O-Demethylation of Arylalkyl Ethers

Aralkyl ethers undergo selective O-Demethylation on treatment with potassium fluoride coated on alumina.     

Electrochemical co-oxidation of C-H acids and methanol as a new route to functionalized cyclopropanes

Electrolysis of dimethyl malonate or methyl cyanoacetate in methanol in the presence of LiCl in an undivided cell leads to formation of 1,1,2,2-cyclopropanetetracarboxylic derivatives.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1835–1836, October, 1994.This work was supported by the International Science Foundation (Grant No MHY 000).     

Syntheses of (±)-thuriferic acid ethyl ester, its analogues and (±)-picropodophyllone

(±)-Thuriferic acid ethyl ester, its analogues as well as (±)-picropodophyllone have been prepared. The synthetic strategy is based on the utility of vicinal dianions derived from α-aroylsuccinic esters.     

Bromination of tri(isopropyl)boroxine and asymmetric synthesis of (2-cyano-3,3-dimethylcyclopropyl)boronic esters

Bromination of triisopropylboroxine to tris(1-bromo-1-methylethyl)boroxine is far more facile than -bromination of sec-alkylboronic esters. Normal fluorescent room light is sufficient to initiate the free radical reaction, which can be carried out as a titration. The steric environment for replacement of the bromine by lithioacetonitrile and subsequent asymmetric insertion of a chloromethyl group into the carbon---boron bond is more highly hindered than what has been studied previously, and the pinanediol ester proved to be the only useful chiral boronic ester in such circumstances. Cyclization of the cyano-substituted boronic ester to the corresponding cyclopropylboronic ester yielded a mixture of diastereomers, presumably the result of base-induced epimerization of the initially formed major isomer having the boronic ester and cyano groups trans.     

纳米固体超强酸S2O82- 催化合成正、异冰片酯的研究

以冰片、异冰片、乙酸、丙酸、丁酸、异丁酸为原料, 首次采用纳米固体超强酸 /ZrO₂催化合成了8个冰片、异冰片酯. 酯化率42%～98%, 反应选择性好, 产物用¹H NMR, ¹³C NMR和IR进行结构确证. 这些酯(除了乙酸冰片酯和乙酸异冰片酯外)的合成未见文献报道.     

纳米固体超强酸S_2O_8~(2-)催化合成正、异冰片酯的研究

以冰片、异冰片、乙酸、丙酸、丁酸、异丁酸为原料,首次采用纳米固体超强酸S2O28-/ZrO2催化合成了8个冰片、异冰片酯.酯化率42%～98%,反应选择性好,产物用1HNMR,13CNMR和IR进行结构确证.这些酯(除了乙酸冰片酯和乙酸异冰片酯外)的合成未见文献报道.     

The Synthesis of N‐(Glycosylthioureylene)‐aminothiophosphonic and ‐diaminothiophosphinic O‐aryl Esters

Reactions of O‐aryl dihydrazinothiophosphinates ( 4, 5 ) or O,O′‐diarylhydrazinothio‐phosphonates ( 2 ) with glycosyl isocyanates ( 6 ) gave corresponding N‐(glycosylthioureylene)‐aminothiophosphonic and ‐diaminothiophosphinic O‐aryl esters. Their structures were confirmed by IR, ¹H NMR, ³¹P NMR, MS and elemental analyses.     

Low‐temperature side‐chain cleavage and decarboxylation of polythiophene esters by acid catalysis

Solubility switching of polymers is very useful in thin layer processing of conjugated polymers, as it allows for multilayer processing and increases the stability of the polymer. Acid catalyzed thermocleavage of ester groups from thiophene polymers carrying primary, secondary, and tertiary substituents have been examined by TGA‐MS using different sulphonic acids. A substantial lowering of the cleavage temperature is observed, and the ester cleavage can even be performed in situ on roll‐to‐roll‐coated films on polyethylene terephthalate (PET). © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Palladium-Catalyzed Hydroesterification of Alkenes in the Presence of Molecular Hydrogen

The effects of molecular hydrogen on the palladium-catalyzed alkene-alcohol-carbon monoxide and alkene-formate reactions have been studied. Yields of esters were generally increased, especially in the alkene-formate reaction, in which an improvement up to 46% yield has been observed. A possible explanation is proposed in which the molecular hydrogen promotes the oxidative addition of formate to palladium. Decarbonylation of formate ester is unlikely to be the initial step.     

新型金属胶束模拟酶对羧酸酯与磷酸酯的催化水解

报道了三种新的含醇羟基、胺基或咪唑基长链配体与铜锌离子构成的金属胶束对几种羧酸酯与磷酸酯底物催化水解动力学。结果表明,设计的金属胶束N-十四烷基-2-(N-2'-羟乙基氨基甲基)咪唑锌铜(2a,2b)在共胶束CTAB(溴化十六烷基三甲铵)存在下,对强配位羧酸酯对硝基苯酚-2-吡啶甲酸酯具有很强的催化水解能力,对磷酸酯对硫磷具有很高的反应性,2a,2b的醇羟基参与了对弱配位底物羧酸酯及磷酸酯的进攻,对不同电荷性质的羧酸酯底物具有较强的静电选择性。     

双炔化合物的合成与表征

研究了邻苯二甲酸二丙炔醇酯 ,丁二酸二丙炔醇酯和对二丙炔氧基苯的合成方法 ,并用元素分析、IR、1HNMR对其进行了表征。