Synthesis and Biological Activity of Alkane-1,1-diylbis(phosphonates) of Diterpenoid Isosteviol

Russian Journal of Organic Chemistry - Isosteviol reacted with α,ω-dibromoalkanes to give 19-(ω-bromoahkyl) esters which were treated with tetraethyl methylenebis(phosphonate) to...     

Synthesis and Crystal Structure of Isosteviol Derivatives

Isosteviol (ent-16-ketobeyeran-19-oic acid, I) is a tetracyclic diterpenoid with a beyerane skeleton obtained by acid hydrolysis of stevioside.1 Several tetracyclic diterpenoids, specially the kaurenes, have important biological activities. Recent studies on the microbial transformation of isosteviol have revealed that it is metabolized by Cunninghamella bainieri, Actinoplanes sp., Mucor recurvatus, and Cunninghamella blackesleeana to yield five new metabolites.2 The hydroxylation pattern of these bioactive compounds may influence their binding on to the receptors, as was proposed for the Rabdosia diterpenoids. Therefore, the introduction of hydroxyl groups or unsaturated bonds in saturated and non-hydroxylated diterpenoids, like isosteviol, may enhance existing properties or lead to new biological activities. Although some beyeranes have been subjected to biotransformations by fungi,4 there are few report in the literature related the chemical transformation of Isosteviol. In the present study, we try to develop the chemical transformation of isosteviol and other beyeranes in order to obtaining some bioactive compounds with beyerane skeleton. Seven isosteviol derivatives, Ⅱ-Ⅷ, were therefore synthesized and characterized. The X-ray crystal strcture of H(R = H) was also determined.     

Phosphorylated Glycoconjugates Based on Isosteviol,d-Arabinofuranose,and d-Ribofuranose

Russian Journal of Organic Chemistry - First phosphorylated glycoconjugates were synthesized in three stages on the basis of isosteviol, d-arabinofuranose, and d-ribofuranose. In the first stage,...     

Synthesis of Macrocyclic Barbiturates

1,6-diaminohexane reacted with 5-(1,3-dithiolan-2-ylidene)-pyrimidino-2,4,6(1H,3H,5H)-trione and its N, N'-dimethyl derivative to afford two novel macrocycles (a 27-and a 18-membered ring, respectively) in good yield. These new compounds are potential complexating agents.     

Design and Synthesis of Macrocyclic Polyoxazoles

Two macrocyclic polyoxazoles with different sizes and numbers of side chains were designed and synthesized from the linear-type precursors obtained by the iterative application of oxazole formation reaction via effective trimerization or dimerization respectively under highly diluted conditions in one pot.     

基于大环醚和三价卤化铋阴离子的超分子杂化化合物:合成、结构及性质(英文)

基于大环自组装和多卤阴离子合成了有机-无机杂化超分子化合物,[(1,4-PMNH3)·(18-crown-6)]·[(H3O)·(18-crown-6)]2·[(H2O)·(18-crown-6)]·(18-crown-6)·(Bi2Cl9)(1)。化合物属正交晶系,Pca21空间群,a=2.483 0(3)nm,b=1.161 8(3)nm,c=3.316 1(2)nm,V=9.566(2)nm3。并通过其红外光谱、粉末衍射、热重分析和单晶结构分析对化合物进行了充分表征。在转子定子型的超分子化合物1中,大环超分子阳离子和(Bi2Cl9)3-阴离子交错堆积形成包合物结构。并在室温下对其固体荧光性质进行测试表征。通过DSC对其热稳定性进行了详细分析。     

基于大环醚和三价卤化铋阴离子的超分子杂化化合物：合成、结构及性质

基于大环自组装和多卤阴离子合成了有机-无机杂化超分子化合物,[（1,4-PMNH₃）·（18-crown-6）]·[（H₃O）·（18-crown-6）]₂·[（H₂O）·（18-crown-6）]·（18-crown-6）·（Bi₂Cl₉）（1）。化合物属正交晶系,Pca2₁空间群,a=2.4830（3）nm,b=1.1618（3）nm,c=3.3161（2）nm,V=9.566（2）nm³。并通过其红外光谱、粉末衍射、热重分析和单晶结构分析对化合物进行了充分表征。在转子定子型的超分子化合物1中,大环超分子阳离子和（Bi₂Cl₉）^3-阴离子交错堆积形成包合物结构。并在室温下对其固体荧光性质进行测试表征。通过DSC对其热稳定性进行了详细分析。     

Synthesis of Macrocyclic Pyrimidine Derivatives

A reaction was studied of previously unknown 1,3-bis(2-hydroxy-3-chloropropyl)uracil, 1,3-bis(2- hydroxy-3-chloropropyl)-6-methyluracil, and 1,3-bis(2-hydroxy-3-chloropropyl)-5-fluorouracil with 1,3-bis[3-(3-methyl-2H-5-pyrazolon-1-yl)-2-hydroxypropyl]-6-methyluracil.     

三聚联苯醚类大环化合物的合成

在温和条件下, 以3,3 -二溴-4,4 -联苯二酚和1,2-二溴乙烷或1,4-二溴丁烷为原料, 经过两步反应方便地合成了三聚联苯醚类大环化合物4a和4b, 并通过¹H NMR, ¹³C NMR, HRMS对中间体和目标化合物的结构进行了表征.     

Synthesis of Dibridged Macrocyclic Tetraazaparacyclophanes

1,8,22,29-Dibridged-1,8,22,29-tetraaza[8.1.8.1]paracyclophanes were synthesized from 1,8,22,29-tetraaza[8.1.8.1]paracyclophane and 6-bromohexanoyl chloride, new macrocyclic hosts of the cyclophane type were provided.     

Total Synthesis and Structural Revision of a Harziane Diterpenoid

The first total synthesis of nominal harziane diterpenoid 1 is disclosed, whose spectral characteristics did not match those of the reported natural product. Stereochemical analysis and subsequent synthesis of the epimeric tertiary alcohol led to reassignment of configuration of the natural product as shown for 2 . At the heart of the synthesis is an enyne cycloisomerization that sets a key quaternary stereocenter within a cyclobutane with high diastereocontrol. The route features strategies for the synthesis of the highly congested 6-5-7-4 carbon skeleton characteristic of the caged harziane diterpenoids.     

Synthesis and Characterization of Heterobimetallic Zigzag Chains with a Close-packed Structure Based on Macrocyclic Metalloligands

Two new heterobimetallic coordination polymers {[Co(NiL)(H_2O)_3]·4H_2O}_n(1) and {[Cu(NiL)(H_2O)_3]·4H_2O}_n(2) were synthesized based on metalloligand under the same self-assembly conditions. X-ray diffraction analyses reveal that the two compounds involve close-packed zigzag chains, which expand into various three-dimensional supramolecular frameworks through the second interactions such as hydrogen bonds and π···π stacking interactions. In these two compounds, NiL as a bridging ligand chelates the metal ion nodes via two oxamido carbonyls and carboxylate oxygen atom. The central Co(Ⅱ) and Cu(Ⅱ) ions in 1 and 2 both exhibit distorted octahedral coordination geometry. They are bridged by macrocyclic oxamido metalloligands fusing the zigzag chains with a ‘‘head-to-tail' arrangement. The Ni(Ⅱ) ion in metalloligand is coordinated by four nitrogen atoms with the [NiN4] chromophore exhibiting distorted planarity. The two investigated compounds were further characterized by thermogravimetric analysis and FT-IR spectroscopy. The fluorescent properties of 1 and 2 in the solid state were also investigated.     

系列大环草酰胺配合物的合成与表征——推荐一个综合化学实验

采用加热回流和溶剂热两种方法合成了三种大环草酰胺系列配合物,并对所得配合物进行单晶结构解析。使用元素分析、红外光谱、电子光谱、ESR谱对配合物进行了表征和性质研究。该实验原料简单易得,实验方法简便易行,可操作性强,有利于培养学生的实践能力和创新能力。     

基于四硫富瓦烯新型大环化合物的合成、结构与氧化还原性质

以四硫富瓦烯(TTF)和氯甲基噻吩为原料, 在碱性条件下合成了一个新的基于TTF大环分子1. 化合物1的结构经元素分析、核磁共振氢谱、质谱和X衍射单晶结构确认. 化合物1属单斜晶系, 空间群P2(1)/n, 晶胞参数: a＝0.97220(19) nm, b＝1.2366(3) nm, c＝1.6051(3) nm, β＝95.41(3)°, V＝1.9211(7) nm3, Z＝2, Dc＝1.621g/cm3, F(000)＝960, μ＝1.032 mm－1, R＝0.0333, wR＝0.1000 [I＞2σ(I)]. 循环伏安结果显示化合物1有两对氧化还原峰, 氧化还原过程不可逆.