Synthesis from d-mannose of 1,4-dideoxy-1,4-imino-l-ribitol and of the α-mannosidase inhibitor 1,4-dideoxy-1,4-imino-d-talitol

The syntheses of 1,4-dideoxy-l,4-imino-L-ribitol and of 1,4-dideoxy-l,4-imino-D-talitol from D-mannose are described. 1,4-Dideoxy-l,4-imino-D-talitol is a specific and competitive inhibitor of human liver α-mannosidase $\text{in vitro}$ and also blocks the lysosomal catabolism of asparigine-linked glycans of glycoproteins $\text{in vivo}$.     

CRYSTAL AND MOLBCULAB STBDCTDBBS OF QUINOXALINE 1,4-DIOXIDB AND 2,3-DMBTHYLQUINOXALINE 1,4-DIOXIDE

<正> Quinoxaline 1,4-dioxide (QO2), C8HsN2O2, Mr=162.14,monoclinic, space group P21,a = 4.112(2), b = 7.402(3), c = 11.378(8) A,β= 94.69(5)°, V=345.1A3,Z= 2,Dc= 1.56 g/cm3, R= 0.032 for 409(I>3.0 O(I)) reflections. The QO2 molecule is planar with average N-O bond length of 1.291(5)A and average N-O bond order of 1.35. 2,3-Dimethylquinoxaline 1,4-dioxide (QM2O2), C10H10N2O2,Mr = 90.20, orthorhombic,space group Pbca,a =7.647(1), b = 14.943(3), c =15.656(5)A, V =1789.1 A3,Z = 8;Dc=1.41 g/cm3,R=0.030 for 655 (I> 3.0 σ(I)) reflections. The QM202 molecule is also planar with average N-O bond length of 1.301A, and average N-0 bond order of 1.31.     

顺1,4及反1,4聚丁二烯共混及共聚物结晶形态结构研究

本文用电镜、电子衍射及DSC等研究了顺1,4PB及反1,4PB的共混及共聚物的形态结构。观察了室温下两相结构分布随组分变化的规律及反1,4PB含量对顺1,4PB低温结晶、片层厚度和球晶大小的影响。进一步讨论了这两种不能形成类质同象结构物质结晶的相互影响。     

Synthesis and Crystal Structure of 1,4-Bis(2-hydroxymethylphenyl)-1,4-dioxabutane

1 INTRODUCTION Macrocyclic ligands and their metal complexes have received much attention due to their applications in ion transport, ion separation and as models in biomimic researches[1~7]. The synthetic methods of macrocyclic ligands and their metal complexes are mainly divided into three kinds[8]. The first one is synthesizing free ligand, then forming the metal complexes; the second is template synthesis; and the third is synthesizing the end-off or side-off precursor ligand, then c…     

Synthesis and rearrangement reactions of 1,4-dihydrospiro[1,4-methanonaphthalene-9,1′-cyclopropane] derivatives

Reactions of benzyne with ester derivatives of spiro[2.4]hepta-4,6-dien-1-ylmethanol were performed. By rearrangement reaction of cyclopropyl methanol units of ((1s*,1′R*,2R*,4′S*)-1′,4′-dihydrospiro[cyclopropane-1,9'-[1,4]methanonaphthalen]-2-yl) methyl 3,5-dinitrobenzoate (13) and its isomer (14), corresponding allyl chlorides were obtained. Two rearrangement products were obtained from bromination of compound 13 with an equivalent amount of Br₂. A naphthalene derivative including allyl and CHO moiety was formed for reactions from compounds with epoxide of 13 and 14 with NaN₃ by sequential rearrangements. Formations of products are discussed.     

丁二烯的顺-1,4聚合

丁二烯可通过1,4加成或1,2加成进行聚合.1,4加成可能生成顺-1,4链节,也可能生成反-1,4链节;1,2加成则可能形成全同立构或间同立构的聚合物.一般游离基或离子型聚合的产物多半为包含各种链节的无规聚合物(见表1).例如用钠或钾聚合的     

1,4-二氢吡啶的合成研究进展

1,4-二氢吡啶(1,4-DHPs)是具有广泛生理活性和应用价值的重要氮杂环化合物.随着绿色有机合成化学的发展,1,4-DHPs的绿色合成和新合成方法在近些年取得了一些重要研究成果,弥补了Hantzsch反应的传统合成途径的一些不足,如环境友好、合成效率、产物结构单一和反应类型匮乏等.对2010年以来Hantzsch反应的绿色合成和新合成方法进行综述,全面地介绍了Hantzsch反应中绿色溶剂、绿色催化剂和绿色合成技术的应用,以及基于新砌块发展出合成1,4-DHPs的新反应研究现状,系统地分析了Hantzsch反应的绿色合成及新型反应的合成策略特点,详细地阐述反应底物、反应条件和产率,进而从新反应的绿色合成化和手性合成等方面对该领域的研究方向进行了探讨.     

Über 2,5-Endimino-1,4-dithiane

Zusammenfassung Die Untersuchungen über die Reaktion zwischen 2,5-Dihydroxy-1,4-dithianen und Aminen der allgemeinen Formel R–NH₂ und R–NHNH₂ wurden fortgesetzt. Aus 2,5-Dihydroxy-1,4-dithian (I) und Ammoniak bildet sich das trizyklische System des 2,5-Di-(N-2,5-endimino-1,4-dithianyl)-1,4-dithians. Dagegen reagiert 2,5-dimethyl-2,5-dihydroxy-1,4-dithian mit Ammoniak zu 2,5-Dimethyl-2,5-endimino-1,4-dithian. Weiters gibt I mit Thiosemikarbazid N-Thioureido-2,5-endimino-1,4-dithian. Um zu wasserlöslichen Derivaten des Ringsystems zu gelangen, die einer pharmakologischen und bakteriostatischen Untersuchung unterzogen werden können, wurden die zur Salzbildung fähigen Verbindungen N--Diäthylaminoäthyl-2,5-endimino-1,4-dithian und N-Isonicotinsäureamido-2,5-endimino-1,4-dithian hergestellt.Herrn Prof. Dr.F. Wessely zu seinem 60. Geburtstag in aufrichtiger Verehrung gewidmet.     

The reaction of α-phenethyl radicals with 1,4-benzoquinone and 2,6-di-tert-butyl-1,4-benzoquinone

The absolute rate constant for 1,4-benzoquinone (BQ) irreversibly trapping α-phenethyl radicals (3) has been determined as 4.4×10⁶ M⁻¹ s⁻¹ at 43 °C using acyclic cis azoalkane 9c as a radical precursor. These reactants afford the hydroquinone mono ether 4 at 30 °C but a mixture of products at elevated temperature. 2,6-Di-tert-butyl-1,4-benzoquinone (DTBQ) also reacts with 3 but the cyclohexadienone products are thermally labile.     

Synthesis and Crystal Structure of N,N''''-Diphenyl-3, 6-diethyl-1,4-dihydro-s-tetrazine-1,4-dicarbonamide

1INTRODUCTIONIthasbeenarousedmoreandmoreinterestsinces-tetrazinewasfirstsynthesizedbyHautgschin1900[1].Thesynthesisofdihydroderivativeof3,6-dimethyl-s-tetrazinewasreportedindetailbySkorianetz[2].UsingX-ray,Jennison[3]foundthat1,6-dihydro-s-tetrazinehashom…     

由2-羟基-1,4-萘醌合成2-乙氧基-1,4-萘醌

由2-羟基-1;4-萘醌合成2-乙氧基-1;4-萘醌;乙氧基萘醌; 羟基萘醌; 乙醇; 硝酸; 回流     

1,4-二氧六环的光电离解离

采用同步辐射光源、飞行时间质谱和分子束方法研究了1．4-二氧六环的光电离解离过程．由光电离效率曲线得出离子产物的出现势，计算了产物的生成焓．若重分析了m／e=28,29.41等离子碎片的解离通道以及离子碎片的可能结构，提出1、4-二氧六环在光电离解离过程中发生了重排反应     

1,4-二氢吡啶衍生物的电化学行为

1;4-二氢吡啶衍生物的电化学行为;循环伏安法     

稀土顺-1,4聚丁二烯结晶度计算

本文根据X-射线衍射强度理论,定义了结晶度计算公式的校正因子,对大角X-射线衍射(WAXD)图谱,按图解分峰法导出了Ln-PB结晶度计算公式。木文所讨论的方法可适用于其它晶性高聚物结晶度计算。     

Diffusion Studies on Polystyrene in 1,4-Dioxane

The diffusion behavior of polystyrene with narrow molecular weight distribution at 20℃ in 1, 4-dioxane was investigated by the photon correlation spectroscopy. The cumulant method was employed for the analysis of the intensity-intensity autocorrelation function measured over a wide range of the scattering vector. The diffusion coefficient D was determined as the function of concentration C in the molecular weight range of 3. 0×104-1. 20×106. In a low concentration range, D was found to be linearly dependent on C, which has been found for some other systems. The dependence of D on molecular weight at infinite dilution can be written as an empirical formula D0 = kDM-γ M, the exponent γ(0. 576 ±0. 01) is in good agreement with the result of the scaling theory.     

Über das 2,5-Dioxy-1,4-dithian

Zusammenfassung In Fortsetzung unserer Arbeiten wurde versucht, das 2,5-Endoxy-1,4-dithian als den Grundkörper dieses bicyclischen Ringsystems herzustellen. Die Bemühungen blieben bisher erfolglos; doch wurde eine einfache Darstellungsmethode für das 2,5-Dioxy-1,4-dithian gefunden. Die Reaktion dieser Verbindung mit Semicarbazid führt zu einem Derivat, das als erster Vertreter des Ringsystems eines 2,5-Endimino-1,4-dithians angesprochen wurde. Mit Phenylhydrazin entsteht dementsprechend das N-Anilido-2,5-endimino-1,4-dithian, während mit Anilin ein 2,5-Dianilido-1,4-dithian erhalten wurde. Die Reaktion mit -Methyl-phenylhydrazin wurde erörtert. Zur Konstitutionsbestimmung der erhaltenen Produkte wurden besonders die hydrierende Desulfurierung und die Diskussion der UR-Spektren herangezogen.Mit 3 Abbildungen.     

腐殖酸催化合成1,4-二氢吡啶类化合物

芳醛、乙酰乙酸乙酯(甲酯)和乙酸铵为原料,用腐殖酸催化一锅法合成1,4-二氢吡啶类化合物.该法产率较高,操作简单.催化剂易于回收再利用,环境友好.