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1.
3-甲酰基色酮1a~1h与马尿酸反应,生成缩合产物色酮-3-基吖内酯2a~2h,水解后得到相应的β-(取代色酮-3-基)-α-丙氨酸3a~3h.  相似文献   

2.
Polymer-supported reagents for organic synthesis are enjoying a renewed popularity with the emergence of combinatorial chemistry in recent years1. 4-(Arylseleno)morpholines formed in situ are useful -seleno-introducing reagents for saturated aldehydes2. -Sele- noaldehydes, as a frequently used intermediates, can be converted into -haloaldehydes by halogenating reaction3. However, organic selenium reagents always have a foul smell and are quite toxic, which is often problematic in organic sy…  相似文献   

3.
Propyl O-(α-L-rhamncpyranosyl)-(1→3)-[2,4-di-O-(2s-methylbutyryl)-α-L-rham-nopyranosyl]-(1→2)-(3-O-acetyl-β-D-glucopyranosyl)-(1→2)-β-D-fucopyranoside (1), the tetrasac-charide moiety of Tricolorin A, was synthesized in total 23 steps with a longest linear sequence of 10 steps, and overall yield of 3.7% from D-Glucose. The isomerization of the dioxolane-type berzyli-dene in the presence of NIS/AgOTf was observed. Tetrasaccharide 1 exhibited no activity against the cultured P388 cell as Tricolorin A did.  相似文献   

4.
螺环倍半萜(±)-α-花柏烯-3-酮的全合成   总被引:1,自引:0,他引:1  
通过萜品油烯 ( Terpinolene)与 2 ,4-二氧代戊酸甲酯的 de Mayo反应得到 [2 +2 ]光加成产物 ,经反aldol重排 ,再环合成具有螺 [5 ,5 ]十一烷结构的花柏烯基本碳架 ,进而对其官能团进行化学修饰 ,完成了螺环倍半萜 (± ) -α-花柏烯 -3 -酮的全合成 .  相似文献   

5.
马桂林  贾定先  仇立干  石慧  陈蓉 《电化学》2002,8(3):321-326
以Ba0 .95Ce0 .9Y0 .1O3-α氧化物陶瓷为固体电解质 ,以多孔性Pt为电极材料 ,分别组成氢、氧浓差电池和氢_空气燃料电池 ,测定了 6 0 0~ 10 0 0℃范围内的浓差电池电动势 ,燃料电池的放电性能和电极极化性能 .结果表明 ,Ba0 .95Ce0 .9Y0 .1O3-α在氢气氛中几乎是一个纯质子导体 ,在氧气氛中是氧离子与电子空穴的混合导体 ,氧离子迁移数在 0 .3~ 0 .5之间 ,在氢_空气燃料电池条件下显示出混合离子 (质子 +氧离子 )导电性 ,总离子迁移数大于 0 .9.该燃料电池性能良好 ,Pt电极极化性能很小 ,最大输出电流密度为 6 80mA·cm- 2 (10 0 0℃ ) ,最大输出功率密度为 16 0mW·cm- 2 (10 0 0℃ ) .  相似文献   

6.
During the past decades enormous progress was made in asymmetric catalytic synthesis, an well-known example is BINAP1, the chiral hydrogenation synthesis of S-(+)-naproxen catalyzed by BINAP-Ru dicarboxylate complexes provides excellent enantioselectivity (up to 99% ee) and good chemical yield (92%), however the pressures is relatively high (135-150 atm) and the (S)-BINAP-Ru(III) complex is very expensive. This problem may present a practical limitation. In recent years new methodolo…  相似文献   

7.
为了寻求新颖的抗糖尿病药物, 我们将芳香醛、对溴苯乙酮和磺胺嘧啶通过一步反应直接合成了16个未见报道的含有磺胺嘧啶结构的β-氨基酮化合物, 制备方法简便、反应条件温和, 收率为10.0%~80.1%. 所制备的化合物通过1H NMR, 13C NMR, MS和HRMS进行结构表征与确证. 对这些化合物进行α-葡萄糖苷酶抑制活性初步检测, 结果表明部分化合物在低浓度范围(8.1~9.3 nmol•mL-1)具有一定的α-葡萄糖苷酶抑制活性.  相似文献   

8.
The title complex was synthesized in an aqueous solution and its crystal structure was determined by X-ray diffraction. The crystal crystallizes in a triclinic system, space group P1 with a=1.306 3(2) nm, b=1.319 4(4) nm, c=1.950 2(4) nm, α=90.597(14)°, β=93.998(11)°, γ=94.093(13)°, V=3.344 1(12) nm3, Z=2, the final R indices are R1=0.065 4, wR2=0.126 2 respectively. The complex contains a novel tetranuclear cluster cation with four Er3+ ions connected by four μ3-OH ions and six bridging carboxyl groups. Each erbium ion is coordinated by three μ3-OH, three carboxylic oxygen atoms from three α-alanine and two oxygen atoms from water molecules, forming a square-antiprismatic coordination polyhedron.  相似文献   

9.
The eudesmane derivative, (-)-10-epi-α-cyperone 1, is widely used as a chiral starting material for the synthesis of other fused-ring sesquiterpenes1. The first synthetic work was reported by Howe and co-workers via condensation of (+)-dihydrocarvone 2 with 1-diethylaminopentan-3-one methiodide in 32% yield2. Previously, our group reported the synthesis of compound 1 by treating ketone 2 with ethyl vinyl ketone (EVK) directly under different conditions1a, but the yields were not satisfacto…  相似文献   

10.
L-酪氨酸经O-苄基化和重氮化反应得到关键中间体--手性3-(对苄氧基苯基)-α-羟基丙酸(4); 4经酯化、氨化和环化反应合成了(S)-(-)-5-对苄氧基苄基-2,4-噁唑烷二酮,总收率10%, 95.4%e.e.,其结构经1H NMR和HR-MS表征.  相似文献   

11.
芳氧乙酸-3-(α-吡啶基)丙酯的合成及生物活性研究   总被引:4,自引:0,他引:4  
以苯氧乙酸类化合物为母体分子,设计并合成了16种芳氧乙酸-3-(α-吡啶基)丙酯新化合物,探讨了反应条件对产物收率的影响.通过元素分析、IR及′HNMR,确证了化合物的结构.其中2种化合物经生物活性测定表明具有较高的除草活性。  相似文献   

12.
A new chiral Schiff base derived from carbohydrate, methyl-4,6-O-benzylidene-3- deoxy-3-(salicylideneamino)-α-D-altropyranoside, has been synthesized by reacting methyl 3-ami- no-4,6-O-benzylidene-3-deoxy-α-D-altropyranoside with salicylaldehyde in methanol and charac- terized by IR, 1H NMR, 13C NMR, MS, elemental analysis, and X-ray crystal structure analysis.The crystal belongs to orthorhombic, space group P212121 with a = 8.0856(16), b = 10.786(2), c = 22.690(5) -, V = 1978.8(7) -3, Z = 4, Mr = 385.40, Dc = 1.294 g/cm3, μ = 0.095 mm-1, F(000) = 816, the final R = 0.0379 and wR = 0.0811 for 2597 independent reflections.In the title compound, the pyrano-ring adopts a twisted 1C4 chair conformation.  相似文献   

13.
采用高温固相法制备了BaCe0.8Lu0.2O3-α质子导体。运用X射线衍射仪(XRD)、扫描电镜(SEM)对该材料的物相结构、微观形貌进行了表征。在500~900℃温度范围内,应用交流阻抗谱和气体浓差电池方法研究了材料在不同气体气氛中的离子导电性和氢-空气燃料电池性能。结果表明,BaCe0.8Lu0.2O3-α材料为单一斜方晶结构,具有良好的致密性。在500~900℃温度范围内,干燥或湿润的氮气、空气和氧气中,材料的电导率随着氧分压增大稍有增大。在湿润的氢气中,材料表现为纯的质子导电性。在以该材料为固体电解质的氢-空气燃料电池条件下,材料表现为质子、氧离子和电子的混合导电性,其中离子导电性始终占主导;氢-空气燃料电池在900℃下的最大输出功率密度为92.2mW·cm-2,高于我们以前报道的BaCe0.8RE0.2O3-α(RE=Pr,Eu,Ho,Er,等)材料。  相似文献   

14.
Oxazolineshavedemonstratedwideutilityinvariouschemicalfields,suchasinasymmetricsynthesis,asaco ordinationligand ,inmedicinalandmacromolecularsynthesis ,andasaprotectinggroupofcarboxylicacids[1~ 3] .Variousmethodshavebeenadvancedforthepreparationof 2 oxazolinesfromthereactionofβ aminoalcoholswithcarboxylicacids,esters,nitriles ,oraldehydessinceitsappearance[1~3] .Reagentssuchascomplexesorstrongacidsorbaseswereusuallyneededinthesevarioussyntheticmethods.Thereactiontakeslongtimetocompletion .…  相似文献   

15.
α-{3-[2-hydroxy-3-(N-methyl-N-hydroxyethylamino)propoxy]propyl}-ω-butylpolydimethylsiloxanes Ⅲ with various moleculax weights were prepared by epoxy addition of α-[3-(2,3-epoxy-propoxy)propyl]-ω-butylpolydimethylsiloxanes Ⅱ and Nmethylmonoethanolamine.At each step.the outcome compounds were characterized through FT-IR and NMR spectra,the results showed that each step was successfully carried out and objective products were achieved.  相似文献   

16.
用高温固相反应法合成了非化学计量组成的Ba1.03Ce0.5Zr0.4La0.1O3-α质子导体.粉末X射线衍射(XRD)结果表明,该材料为单一钙钛矿型BaCeO3斜方晶结构,在高温下、CO2或水蒸气气氛中具有较高的稳定性.扫描电子显微镜(SEM)观察分析表明,材料经1550℃烧结20h非常致密.在500~900℃温度范围内,用交流阻抗谱技术测定了材料在湿润氢气和湿润空气气氛中的电导率;用气体浓差电池方法测定了材料在湿润氢气、湿润空气气氛中和氢-空气燃料电池条件下的离子迁移数,研究了材料的离子导电特性,并与化学计量组成的BaCe0.5Zr0.4La0.1O3-α材料进行了比较.结果表明,在500~900℃温度范围内、湿润氢气气氛中,Ba1.03Ce0.5Zr0.4La0.1O3-α材料的质子迁移数为1,是一个纯质子导体.在湿润空气气氛中,材料的氧离子迁移数为0.688~0.170,质子迁移数为0.218~0.017,是一个氧离子、质子和电子空穴的混合导体.在氢-空气燃料电池条件下,材料的离子(氧离子+质子)迁移数为0.990~0.796,是一个氧离子、质子和电子的混合导体.与化学计量组成的BaCe0.5Zr0.4La0.1O3-α材料相比较,在相同实验条件下非化学计量组成的Ba1.03Ce0.5Zr0.4La0.1O3-α材料具有较高的电导率和离子迁移数.  相似文献   

17.
Eudesmanederivativeshavebeendrawingconsiderableattentionduetotheirwidespectrumofbiologicalproperties,particularlyantifeedant,cellgroWthinhibitoryandplantgroWthregulatingactivitiesl'2.Recently,twoepimericeudesmanederivatives( )-5a-hydroxy-6-selinene1and(-)-56-hydroxy-6-selinene2wereisolated3fromtheaerialpartsofCSubtraPicaFMell.,andtheirstructuresweredeterminedbyspectroscopicmethods.Herein,wereportafacilesynthesisofbothtwodiastereomers1and2from( )-dihydrocarvone3infivesteps,usingtheregioselect…  相似文献   

18.
1-(4-安替比林)-3-(3-硝基苯胺)三氮烯分光光度法测定镉(Ⅱ)   总被引:1,自引:0,他引:1  
合成了一种新的显色剂三氮烯试剂1-(4-安替比林)-3-(3-硝基苯胺)三氮烯(ANTA),并研究了该显色剂与镉(Ⅱ)的显色反应。在Tween-80存在下及pH 10.2的硼砂-氢氧化钠缓冲溶液中,显色剂ANTA与镉(Ⅱ)形成2∶1的稳定络合物。其最大吸收波长位于508 nm波长处,表观摩尔吸光率为3.4×105L.mol-1.cm-1。镉(Ⅱ)的质量浓度在30.0~450μg.L-1范围内符合比耳定律,方法的检出限(3σ/k)为10.0μg.L-1。方法用于废水样品中微量镉(Ⅱ)的测定,测定结果与原子吸收光谱法相一致,平均回收率为103.5%,平均相对标准偏差(n=6)为4%。  相似文献   

19.
Triazole derivatives are widely studied, because they represent the largest group of modern fungicides and are widely used both in human and veterinary therapy and in agriculture. We synthesized the title compound in which the thiophene ring was substituted by a 1,2,4-triazole group, a phenacyl group, a phenylaminol group and a benzene ring.  相似文献   

20.
由邻苯二甲酸酐为原料,经中间体3-羟基苯酞(3),再经溴丙烯及锡存在下3的烯丙基化、硼氢化氧化、铬酐氧化、二甲基锌甲基化,共6步反应合成了3-(3'-羟基丁基)异苯并呋喃-1(3H)-酮.  相似文献   

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