Enantiodivergent Synthesis of Benzoquinolizidinones from L-Glutamic Acid

Benzoquinolizidinone systems were synthesized in both enantiomeric forms from L-glutamic acid. The key chiral arylethylglutarimide intermediate was synthesized from dibenzylamino-glutamate and homoveratrylamine. Aldol reaction of the glutarimide afforded a mixture of syn and anti-aldol adducts. Subsequent regioselective hydride reduction of the glutarimide carbonyl followed by N-acyliminium ion cyclization afforded a product with opposite absolute configurations at C3 and C11b. Cope elimination of the dibenzylamino group then converted the two diastereomers into enantiomers.     

L-谷氨酸与维多利亚绿S作用机理及应用研究

用紫外-可见光度法、共振散射光谱法探讨了在弱酸性介质中,碱性染料维多利亚绿S与酸性氨基酸L-谷氨酸相互作用机理,认为L-谷氨酸分子通过盐键和氢键相互结合成含有亲水性基团的分子链,这条分子链可以将维多利亚绿S的疏水性基团包在里面,使其亲水性基团朝外,并通过盐键和氢键与维多利亚绿S作用形成大的聚合体,其聚合体体积远远大于染料自身聚集体的体积,使溶液颜色变深,分子光谱吸收值增加.并优化了反应体系酸度、反应物用量、反应时间、加试剂顺序等影响反应速度的因素,确定了最佳实验条件,建立了测定L-谷氨酸的方法.线性范围为10mg/L～100 mg/L,相关系数为0.9989.直接测定样品中谷氨酸获得满意结果.     

L-谷氨酸桥联的卟啉二联体的合成和表征及其CD光谱研究

通过L-谷氨酸(乙酰基保护)与二氯亚砜反应制备的二酰氯和单羟基卟啉(M-PH₂)反应,合成了L-谷氨酸桥联的卟啉二联体,用红外光谱、 电子吸收光谱、 核磁共振氢谱、 元素分析和质谱对化合物的结构加以确证,通过圆二色谱(CD)研究了化合物的手性特征.     

Synthesis and Molecular Recognition of Novel Cyclic Pseudopeptides Containing L-Glutamic Acid or L-Aspartic Acid Backbones

Novel cyclic pseudopeptides containing L-glutamic acid or L-aspartic acid backbone structures were efficiently synthesized and characterized. Their chiral recognition properties for L- and D-amino acid methyl ester hydrochloride were discussed also.     

Synthesis of L-Lysine and L-Glutamic Acid Derivatives with Long Alkyl Chains and Polycondensation of Langmuir-Blodgett Films

Two esters of L-lysine and L-glutamic acid containing long alkyl groups were synthesized and their polycondensation in monolayers and multilayers was investigated. The pressure-area isotherms of the ester of L-lysine depend markedly on the time of residence at the air-water interface. The change of FT-IR spectra of the deposited film, which can be lifted as a Z-type film, indicates that polycondensation can occur in the monolayer at 10°C without any treatment. The spectrum of the film cast from chloroform hardly changed with time. These results lead to the conclusion that a regular arrangement of monomer molecules in the monolayer, where the amino and ester carbonyl groups are concentrated, is more suitable for the polycondensation. The ester of L-glutamic acid can also form stable monolayers which can be easily deposited on a hydrophobic plate as a Y-type film by the Blodgett technique. The polycondensation of multilayers under an atmosphere of triethylamine was investigated by IR spectroscopy. It indicates that the condensation in multilayers proceeds via intermolecular and intramolecular reactions, by which poly(L-glutamate) derivatives and 2-pyrrolidone derivatives are formed, respectively. The condensation in the bulk crystalline powder gives exclusively the 2-pyrrolidone derivative by intramolecular reaction. These results suggest that the monomer molecules in the multilayers are favorably aligned for the intermolecular reaction, in contrast to the situation in the bulk crystalline powder.     

由醋酸去氢表雄酮合成熊去氧胆酸

探索了用植物源商业原料合成熊去氧胆酸的新方法. 以醋酸去氢表雄酮为原料, 以区域选择性烯丙位氧化、 Mistunbu反应和Luche还原为关键步骤, 通过9步反应, 以38.6%的总收率合成了熊去氧胆酸. 其中, 关键中间体4由化合物3经改进的烯丙位氧化反应以较高产率获得. 对关键的烯丙基氧化反应的条件进行了优化, 包括溶剂、 氧化剂和反应温度. 该方法原料易得、 产率较高, 并且有效地避免了动物源性原料的风险, 易于实现规模化合成, 因而具有较高的应用价值.     

纳米稀土谷氨酸咪唑三元配合物的合成、表征及抗菌活性研究

合成了6种新型纳米稀土三元配合物。通过元素分析、摩尔电导、红外光谱、紫外光谱、氢谱、碳谱、热重-差热等表征,确定了该类配合物的化学组成为：RE（Glu）3ImCl3·3H2O（RE=La^3＋,Nd^3＋,Er^3＋,Eu^3＋,Y^3＋,Gd^3＋;Glu=L-谷氨酸;Im=咪唑）,TEM电镜测试表明其有一定规则形貌,粒径在30-60 nm。通过抗菌实验对其抑菌效果进行研究,结果表明：6种纳米稀土三元配合物对大肠杆菌、金黄色葡萄球菌和白色念珠菌均有较强的抑制作用（最小抑菌浓度MIC分别约为140,100,250μg·ml^-1）,属于广谱抗菌剂;抗菌效果明显优于非纳米稀土三元配合物、稀土氯化物、L-谷氨酸或咪唑。     

Synthesis of 3-Carboxycoumarins from O-Methoxybenzylidene Meldrum's Acid Derivatives

Reaction of o-methoxybenzaldehydes with Meldrum's acid followed by cyclization in sulfuric acid of the benzylidene derivatives 3a-g affords 3-carboxycoumarins in excellent yields.     

自组装单层上谷氨酸晶体的生长和晶型控制

报道了谷氨酸晶体在L-半胱氨酸自组装单层上的成核和生长。 在L-半胱氨酸单层的诱导作用下,通过改变溶液的pH值,可以制备出不同晶型的L-谷氨酸,这为控制谷氨酸的晶型提供了一个简单的方法。 在pH值为2.0和2.5条件下,可得到六边形片状的β-谷氨酸,而在pH值为3.0和4.0时得到棱柱状的α晶体。 XRD结果表明,α晶体内有少量的β-谷氨酸晶体出现,这可能来自于β-谷氨酸的“二次成核”。     

3-羟基十四酸的合成

以环氧氯丙烷为起始原料,经5步反应合成了3-羟基十四酸,总收率52.48%。以氯癸烷替代溴癸烷做格氏反应,有效地降低了偶联副产物的生成;从中间产物1-氯-2-羟基十三烷直接上氰基,避免了环化后上氰基时生成氢氰酸的危险。     

One-Pot Synthesis of Thiazoles from Pyridazin-3-hydrazidic Acid Derivatives

Several new thiazole derivatives have been synthesized; the reactivity of these compounds toward amines, aldehydes, and hydroxyl amine are reported. New syntheses of pyrimidino[5,4:3,4]pyrazolo[4,3:5,6]pyridazine derivatives also have been achieved.     

A Direct Synthesis of Benzothiophene-3-Carboxylic Acid from Benzothiophene

The direct synthesis of benzothiophene-3-carboxylic acid from benzothiophene utilizing Friedel-Crafts acylation with trichloroacetyl chloride, followed by basic hydrolysis is presented.     

Electrochemical Detection of Epinephrine Using an L-Glutamic Acid Functionalized Graphene Modified Electrode

The development and application of an L-glutamic acid functionalized graphene nanocomposite, modified glassy carbon electrode are reported for the determination of epinephrine. The properties of the nanocomposite were characterized by scanning electron microscopy, ultraviolet-visible absorption spectroscopy, infrared spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. The modified electrode had high sensitivity and strongly catalytic activity for the detection of epinephrine. A linear relationship between the epinephrine concentration and the current response was obtained in the range of 1 × 10^?7 M to 1 × 10^?3 M by differential pulse voltammetry with a limit of detection of 3 × 10^?8 M. The modified electrode was employed to determine epinephrine in urine with satisfactory results.     

Improved Synthesis of 3-Nitrophenylacetic Acid

In the development of certain work in our laboratory, we needed large quantities of 3-nitrophenylacetic acid. This material is very expensive commercially. It therefore became necessary to find a convenient and efficient process since none of the reported procedures is suitable for a large scale preparation of 3-nitrophenylacetic acid. In the first synthesis reported by Frederick et al.¹, 3-nitrobenzyl chloride was converted to 3-nitrophenylaceto-nitrile which was hydrolyzed to 3-nitrophenylacetic acid in 38% yield. The utility of this method for making large quantities of 3-nitrophenylacetic acid is restricted by the high cost of 3-nitrobenzyl halides. The second 2 method published by Jennings² is a multistep process starting with 3-nitrobenzaldehyde and the reported overall yield is 31%. This method also is not suitable for a large scale preparation due to the hazardous nature of the acid azide which is formed as one of the intermediates in this five step sequence. The third method describes the conversion of 3-nitroacetophenone to 3-nitrophenyl-acetic acid by willgerodt reaction.³ Although the starting material 3-nitroacetophenone is inexpensive but the reported yield of 3-nitrophenylacetic acid is only 7%. The high temperature required in the willgerodt reaction causes the reduction of nitro group by sulfur resulting in a bad mixture thus lowering the yield of nitrothio-morpholide (3) and making its isolation difficult.     

3-甲基犬尿喹啉酸衍生物的合成

报道了六个具有潜在生物活性 3 甲基犬尿喹啉酸衍生物的合成 .它们以取代苯胺和 3 甲基 2 酮丁二酸二乙酯为起始原料 ,经加成脱水 ,环化而得到 .其中三个新的含氟化合物的结构分别经IR ,1 HNMR ,MS ,元素分析等表征     

A Chemical Synthesis of 3-Deoxy-D-manno-2-octulosonic Acid from D-mannose

A chemical synthesis of Kdo was achieved via the condensation of a protected D-mannofuranose-5,6-cyclic sulfate with ethyl 1,3-dithiane-2-carboxylate, which is an efficient equivalent for installing an α-ketoester unit as a key step.     

稀土－谷氨酸配合物的pH电位法研究

报道了在生理条件（３７℃，Ｉ＝０．１５ｍｏｌ·Ｌ－１ＮａＣｌ）下用ｐＨ电位法对１５种稀土元素与Ｌ－谷氨酸配合物稳定常数的测定结果。玻璃电极校正用ＭＡＧＥＣ程序进行，各体系中配合物物种的选择及其稳定常数的计算用程序ＭＩＮＩＱＵＡＤ－８２Ａ完成，讨论了“四分组效应”及钇的位置。     

1H-吲唑-3-羧酸的合成

综述了1H-吲唑-3-羧酸的合成方法,并评述了其优缺点;同时介绍了作者在寻找其新合成方法中的一些探索。参考文献28篇。     

3-硝基-2-氨基苯甲酸的合成

以邻苯二甲酸酐为起始原料,经硝化、脱水、酰胺化、霍夫曼重排4步反应合成了3-硝基-2-氨基苯甲酸,总收率19%,其结构经1H NMR, IR和元素分析表征.探讨了酰胺化和霍夫曼重排反应条件对产率的影响.结果表明, n(脲素) ∶ n(3-硝基邻苯二甲酸酐)=2.0 ∶ 1.0,于50 ℃～60 ℃反应5 h～6 h,酰胺化反应收率85%～91%.n(NaClO) ∶ n(3-硝基-2-甲酰胺基苯甲酸)=1.2 ∶ 1.0,于60 ℃反应3 h,重排反应收率94%.