共查询到20条相似文献,搜索用时 0 毫秒
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Yi SHEN Ling XIANG Yong DENG Yu Guo ZHONG Department of Medicinal Chemistry West China School of Pharmacy Sichuan University Chengdu 《中国化学快报》2006,(4)
A convenient synthesis of cis-(±) isomer 1 and trans-(±) isomer 2 of lamivudine starting from benzoyloxyacetaldehyde and l,4-dithiane-2,5-diol is described. The key steps include chlorination of oxathiolane lactol 5 by SOCl2/DMF, followed by coupling with silylated N4-acetylcytosine and deprotection. The overall yield was 42.6 % and 20.1 %, respectively. 相似文献
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Ping Yan BIE Cheng Lu ZHANG Xuan Jia PENG Xin Fu PAN* Department of Chemistry National Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 《中国化学快报》2002,13(9)
Celaphanol A was a diterpene isolated from the stems of Celastrus stephanotifolius1, which have been the subject of continued and growing interest, due to the range of biological activities shown by many members of this family2. Some have been used in traditional medicine3 or as a stimulant4 from ancient times. In order to further study the relationship between the structure and biological activity of the diterpene compound and as an extension of diterpenoid synthesis in our laboratory5, 6, … 相似文献
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The first total synthesis of (±)-3', 7-dihydroxy-4'-methoxyflavan, a naturally occurring flavan, was described.The key step is the cyclization of 1, 3-diaryl-1-propanol by BF3·Et2O. 相似文献
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毛细管气相色谱法测定乳脂中的cis-9,trans-11-共轭亚油酸 总被引:5,自引:0,他引:5
建立了测定乳脂中cis-9, trans-11-共轭亚油酸(CLA)的毛细管气相色谱方法。样品经正己烷-异丙醇提取、甲醇-甲醇钠甲酯化后,进行气相色谱分析;采用程序升温,以保留时间定性,外标法定量。采用该方法测得共轭亚油酸的回收率为100.26%,相对标准偏差(RSD)为1.9%(n=6),检测限为1 mg/L。该方法样品用量少,前处理简单,建立的实验条件准确可靠,不仅可以用来测定cis-9,trans-11-CLA的含量,而且对于乳制品中所含的其他脂肪酸的分析测定也具有指导意义。 相似文献
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De Feng XU Xiao Juan GUO Zhao Hui XU Shao Shun LI School of Pharmacy Shanghai Jiaotong University Shanghai 《中国化学快报》2006,(7)
Shikonin 1 was a key component isolated from the traditional Chinese herbal medicine, Zicao(Lithospermum erythrorhizon Sieb.et Zucc), which possesses multiple biological activities1. There have been many synthetic routes to shikonin, however, all these ro… 相似文献
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利用温和的方法进行了异戊烯基黄酮(±)-abyssinone-VI-4-O-methyl ether,(±)-abyssinone-IV-4’-O-methyl ether,(±)-abyssinone-V-4’-O-methyl ether和(±)-sigmoidin E的全合成研究,同时通过对羟基苯甲醛的异戊烯基化以及在石油醚中低温结晶的方法合成了关键中间体4-羟基-3,5-二异戊烯基苯甲醛.所有新化合物的结构都经过IR,1H NMR,MS,HRMS确认. 相似文献
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CHEMICAL STRUCTURE DEPENDENCE OF THE INTERNAL ENERGY CONTRIBUTION IN RUBBER ELASTICITY 总被引:2,自引:0,他引:2
Juan Sun Xiao-zhen Yang Polymer Physics Laboratory Center for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing China 《高分子科学》2001,(5):447-449
Conformational elasticity theory recently developed has been used to explore the internal energy contribution tothe elastic force f_e/f as a function of strain for poly(cis-1,4-isoprene) and poly(trans-1, 4-isoprene). Calculated f_e/f values arein good agreement with those obtained experimentally. Results show that behavior of f_e/f is mainly contributed by chemicalstructure, or intramolecular interaction, supporting the experimental observations, and that the internal energy contribution isstrain dependent. 相似文献
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《中国化学快报》1998,(4)
Chrysotricine1wasisolatedfromtheChineseherbmedicineHedyotiSChrysotricha'anditssthectUrehasbeenestablishedasanew0-carbolinealkaloidwitha2,5-trans-substitutedtetrahydrofuranylgrouPatitsl-positionbyX-raydiffractionandspectralanalysis.PharmaceuticalstUdiesshowedpotentialantitUmoractivity.Theinterestingbiologicalactivityandthechemistryof6-carb0linesmict[JIehaveattiactedconsiderableattentioninrecentyears.InordertostUdythisstrUctUre-activityrelationshiPfurther,wewereillterestedinthedevelopmento… 相似文献
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ZHANG Chen CHEN Jin-chun ZHENG Guo-jun LI Yu-lin 《高等学校化学研究》2007,23(3):276-279
A highly efficient and convergent approach for the synthesis of octalone 1, the focal intermediate for the synthesis of several sesquiterpenoids, was developed based on the cationic cyclization strategy of the functionalized oxabicyclic template 5. 相似文献
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对四种天然二聚二苯乙烯类化合物Shegansu B (1), Gnetuhainin F (1a), Maackin A (2)以及Cassigarol E (3)的全合成进行了研究. 以3,5-二羟基苯甲酸(4)为起始原料, 经六步反应制得异丹叶大黄素(13)和白皮杉醇(14), 在HRP/H2O2酶催化氧化体系中, 13和14分别进行自身的氧化偶联得到各自的二聚产物. 首次完成了1a, (±)-2和(±)-3的全合成, 并以较文献报道为高的氧化偶联产率合成了(±)-1. 相似文献
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采用密度泛函理论(Demity Function Theory)中的B3LYP方法,在Lanl2dz赝势基组水平上对(PtnMn)±,0(n=1~5)团簇的几何构型进行了全优化,并对基态的能级以及磁性进行了研究.结果表明:PtMn掺杂团簇的自旋多重度比较高,这种性质跟纯Mn团簇相似.并且发现一般情况下Mn原子参与成键数越多,结构越稳定,在成键数相同的情况下,成键的平均键长越短越稳定;其次(PtnMn)±,0团簇的所有稳定结构都表现为铁磁性耦合;掺杂一个Mn原子后的团簇磁性大大增强,磁矩主要来源于未满的d壳层电子,且Mn原子上的局域磁矩远大于Pt原子.随着Pt原子个数的增加,Mn原子的局域磁矩变化不大,但团簇的总磁矩渐渐增大. 相似文献
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The two diarylheptanoids (E)-1-(4'-hydroxy-3'-methoxyphenyl)-7-(4"-hydroxyphenyl) hept-4-en-3-one 1 (Gingerenone C) and (±)-5-hydroxy-1-(4'-hydroxy-3'-methoxyphenyl)-7-(4"-hydroxyphenyl)-3-heptanone 2 were synthesized from vanillin 3 and 4-hydroxybenzaldehyde 9. 相似文献