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6β,7β,14β-Trihydroxy-1α-acetoxy-7α,20-epoxy-ent-kaur-16-en-15-one was isolated from the natural plant of Isodon japonica (Burm.f), Haravar. galaucocalyx (maxim) Hara. The structure was elucidated by means of spectral and chemical studies. In addition, its crystal was determined by single-crystal X-ray diffraction analysis. It crystallizes in triclinic, space group P1, Z = 2, a = 6.3506(4), b = 13.5766(8), c = 15.2777(9) , α = 80.506(1), β = 83.856(1), γ = 88.307(1)o, C25H36O9, Mr = 480.54, V = 1291.64(13) 3, Z = 2, Dc = 1.236 g/cm3, F(000) = 516, μ = 0.093 mm-1, S = 0.988, the final R = 0.0761 and wR = 0.1955. Flack factor is 0.02(19), and the largest peak and deepest hole on the final difference Fourier map are 0.556 and –0.265 e/3, respectively. The X-ray diffraction shows the existence of intermolecular C–H…O (DA) hydrogen bonds between adjacent molecules. 相似文献
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3-Oxo-7αH-eudesma-4-en-9β,12-diol1awasfirstisolatedfromCassinauncatabyKingetal.,anditsstructurewasdeterminedbyhighfieldNMRtechniques;however,theabsoluteconfigurationofC-llremainedunsolved.RecentlyPedroetalreportedthefirsttotalsynthesisof(llS)-3-oxo-7aH-eudesma-4-en-95,l21bfromartemisin2inl3steps'.Herein,wereportafacileprocedureforsynthesisofC-llisomericdiolsandthestereochemistryofnaturaldiol.Oursyntheticrouteisshownasbelow:a)ref5,36%;b)Vilsmeierreagent.30%H202,CH2Cl2.-20"C,lh.62%,c)i.… 相似文献
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Xiu Chao XIE Wen Li MEI You Xing ZHAO Kui HONG Hao Fu DAI 《中国化学快报》2006,17(11):1463-1465
A new degraded sesquiterpene was isolated from the marine actinomycete Streptomyces sp. 0616208. Its structure was elucidated as (1α,4aα,5α, 7β, 8aβ)-5, 8a-dimethyl-decahydronaphthalene -1, 4a, 7-triol on the basis of spectroscopic data. 相似文献
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采用薄层色谱成功地分离了 3,3-乙撑二氧 - Δ5(1 0 ) ,9(1 1 ) -雌甾二烯 - 1 7α( 1 -丙炔基 ) - 1 7β醇的环氧化产物 3,3-乙撑二氧 - 5α,1 0α-环氧 -Δ9(1 1 ) -雌烯 - 1 7α( 1 -丙炔基 ) - 1 7β醇 (简称 Iα)和 3,3-乙撑二氧 - 5β,1 0β-环氧 -Δ9(1 1 ) -雌烯 - 1 7α( 1 -丙炔基 ) - 1 7β醇 (简称 Iβ) ,并对 Iα 和 Iβ进行了定性和定量分析 ,其结果在红外谱图、核磁实验中得到验证。 相似文献
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The title compound, α,α,β,β-5,10,15,20-tetrakis(2-aminophenyl)porphyrin, has been obtained and characterized by single-crystal X-ray diffraction.The crystal belongs to the monoclinic system, space group C2/c with a = 31.804(6), b = 19.314(4), c = 12.872(3) -, β = 90.592(3)°, Z = 4, V = 7907(3) -3, Dc = 1.193 g/cm3, Mr = 1419.67, λ(MoKα) = 0.71073 -, μ = 0.073 mm-1, F(000) = 2984, R = 0.0773 and wR = 0.2045.The crystallographic analysis indicates the existence of N-H…( intermolecular interactions and hydrogen bonds which link the complex molecules into a 3D network structure. 相似文献
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化合物(2)和(3)经分子间和分子内的Diels-Alder反应是合成六氢萘和六氢(或八氢)萘骈呋喃的有效方法,如2与丁炔1,4二酸甲酯反应得4,而3a和3b的分子内Diels-Alder反应分别得5和6。这些化合物都是合成具有高度生物活性物质如ugand-ensidial(7)和forskolin(8)的重要中间体。但这些产物中均含AB反式结构和6β羟基官能团,因此研究如何把△~5转化为5αH.6βOH 相似文献
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以脱氢表雄酮为原料,经羟基乙酰化,羰基亚乙二氧基化,CrO3/3,5-二甲基吡啶氧化,硼氢化钠还原,脱17-位亚乙二氧基,脱3-位乙酰基,用叔丁基二甲基氯硅烷(TBDMSC1)保护3,7-OH,17-位环氧化,17-位开环,脱TBDMSC1保护等十步反应合成了四个新型的17α-乙炔基-5-雄甾烯-3β,7β,17β-三醇(HE3286)衍生物,其结构经1H NMR和MS表征. 相似文献
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Lophenol, cholest-4α-methyl-7-en-3β-ol (1), obtained from Dracaena cochinchinensis (Lour.) S. C. Chen, was structurally modified. It was acetylated to protect 3β-hydroxyl group, and then oxidised by selenium dioxide in acetic acid to give cholest-4a-methyl-8-en-3β, Ta-diol diacetate (3). This compound 3 is unstable in chloroform solution or when heated and easily converted to a diene compound, cholest-4a-methyl-7,14-dien-3β-ol acetate (4). The structures of 3 and 4 were elucidated by means of IR, ^1H NMR, ^13C NMR and MS, and the absolute configuration of 3 was established by X-ray crystallography. The property of 3 was also discussed in this paper. Both 3 and 4 are new compounds and were reported for the first time. 相似文献
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甾体分子中引入7位甲基往往可以增强或改变其生理活性,例如7α,17α-甲基-19-失碳睾丸酮1具有比母体更强的抗生育活性而无雌激素活性。有关光学活性的7-甲基甾体化合物的合成,至今似只见到以光学活性的化合物2合成了7α(β)-甲基雌酮-3-甲醚的衍生物3a,b。本文报道利用我们新近合成的光学活性合成原4来合成标题化合物。 相似文献
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以α/β类蛋白的2种典型折叠类型为研究对象,对205个低相似度蛋白样本中的π-π相互作用进行统计分析.计算结果表明,(α/β)8-barrel折叠中π-π相互作用的分布密度高于经典Rossmann折叠,且在关键的局部区域的差异更加显著;芳香族氨基酸在(α/β)8-barrel结构中更容易形成π-π相互作用;色氨酸对应的3种π-π相互作用组合在(α/β)8-barrel折叠中出现的几率显著高于经典Rossmann折叠;(α/β)8-barrel折叠中π-π相互作用形成复杂π网络的能力强于经典Rossmann折叠.上述结果表明,π-π相互作用在α/β类蛋白的不同折叠类型中存在特异性,其在稳定(α/β)8-barrel结构中的作用强于经典Rossmann折叠. 相似文献
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α-(α’-甲基-卤代苄氧基)-β-(1-咪唑基)-2,4-二氯乙苯硝酸盐的合成与结构表征 总被引:1,自引:0,他引:1
先以间二氯苯、氯乙酰氯和咪唑为原料合成β-( 1 -咪唑基 ) -2 ,4 -二氯 -α-苯乙醇 ( ) ,再以二卤苯为原料合成α-氯 -卤代乙苯 ( a~ d) ,然后 , 分别与 a~ d反应 ,生成α-(α -甲基 -卤代苄氧基 ) -β-( 1 -咪唑基 ) -2 ,4 -二氯乙苯硝酸盐 4个新化合物 ,产率分别为 66.8% ,78.5% ,76.8%和 81 .2 % ,新化合物的结构经元素分析 ,IR和 1H NMR表征 相似文献
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以D-(-)-果糖为手性源,经过丙酮保护、氧化、选择性脱保护、三氟酰化四步反应得到手性酮4。以手性酮4为催化剂,立体选择性环氧化α,β-丙烯酸酯,较高产率和立体选择性地获得了重要的手性中间体α,β-环氧丙酸酯。产率和e.e.值分别达到76%~92%和92%~98%。 相似文献
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5α-表雄甾经Jones氧化与溴化反应制得2α-溴-5α-雄甾-3,17-二酮(3);3与咪唑在DMF/K2CO3体系中反应成功地合成了2,3α-环氧-3β-咪唑-5α-雄甾-17-酮(4),其结构经1H NMR,13C NMR,IR,MS和XRD表征。4属单斜晶系,空间群P21,晶胞参数a=1.061 5 nm,b=0.581 7 nm,c=1.628 9 nm,α=γ=90°,β=105.594°,R1=0.042 9,ωR2=0.114 3。 相似文献