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本文报道了天然昆虫拒食剂茼蒿素的一些新类似物的合成。整个工作以取代的呋喃丙醇为前体, 经间氯过氧苯甲酸氧化、Luche还原、双键环氧化、酸催化的螺环缩酮化以及自由基媒介的脱水反应给出目标产物。 相似文献
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DidemnaketalA是一类具有明显抗艾滋病活性的天然螺环缩酮类化合物[1],但至今未见有关合成及立体化学研究的报道.为进一步研究这类螺环缩酮类化合物的生理活性,我们开展了侧链简化的类似物(如化合物1)的合成研究. 相似文献
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通过IR,1HNMR,13CNMR,UV,MS以及X射线晶体衍射测定方法来确认一类新的手性螺-环丙烷化合物的化学结构.为研究新的螺环/环丙烷类复杂化合物的结构提供了有价值的依据. 相似文献
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果蝇 ( Tephritidae)对水果生产有严重的危害 .热带果蝇寿命较长 ,具有很强的迁徙能力和繁殖能力 .因此开展果蝇生物防治和控制措施的相关研究具有重要的意义 [1,2 ] .Baker等 [3]发现性成熟的雌B.dorsalis果蝇 ,性腺分泌物中包含有螺环缩酮化合物 2 ,8-二甲基 - 1 ,7-二氧杂螺 [5 ,5 ]十一烷 ( 1 ) .Bactrocera Latifrons( Hendel)果蝇的雄性腺体分泌物中也存在螺环缩酮 1 [4 ] ,另外在 rove甲虫腹梢分泌物中也分离出 1 [5] ,螺环缩酮不仅作为性信息素组分存在于许多果蝇腺体中 ,而且作为结构单元存在于许多复杂的有强烈生理活性的天然… 相似文献
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二代螺环树形化合物1,2,3,4,5,6,7,8,9,10,11,12-十二氢-2,2;6,6;10,10-三[3,3-二(烷氧羰基)-1,1-环亚丁基二甲氧基]三亚苯基的合成 总被引:1,自引:0,他引:1
以1,4-环己二酮、丙二酸二乙酯及多元醇等为原料, 经过两次“一锅煮”法合成了六种二代螺环树形化合物1,2,3,4,5,6,7,8,9,10,11,12-十二氢-2,2;6,6;10,10-三[3,3-二(烷氧羰基)-1,1-环亚丁基二甲氧基]三亚苯基螺环树形化合物, 其中烷氧基为异戊氧基、三羟甲基甲氧基、2,2-二溴甲基-3-羟丙氧基、2,2-二羟甲基丙氧基、二羟甲基膦甲氧基和(N-羟甲基-N-二羟甲基氨基乙基)甲氧基. 利用IR, NMR, MS和元素分析对合成的化合物进行了结构认证, 对影响反应的因素进行了讨论. 相似文献
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以对苯二甲醛、丙二腈为原料, 合成对苯二甲醛单缩醛, 再与季戊四醇反应得到了2,4,8,10-四氧杂-2,9-二(4-二氰基乙烯基苯基)螺[5.5]十一烷, 经水解, 与丙二腈反应, 制备了中间体2,4,8,10-四氧杂-2-(4-二氰基乙烯基苯基)-9-(4-甲酰基苯基)螺[5.5]十一烷(3). 用乙酸酐保护的对苯二甲醛单缩醛与间苯二酚反应, 制备了杯芳烯中间体(6). 将化合物6与过量的化合物3反应, 得到中间体7, 经水解后与过量的化合物6反应, 得到了4,6,10,12,16,18,22,24-八羟基-2,8,14,20-四-{(联三-(3-苯基-2,4,8,10-四氧杂螺[5.5]十一烷基))-(4-(2-(4,6,10,12,16,18,22,24-八羟基)杯芳基)苯基)}杯芳烃螺环树形大分子化合物(9). 总收率为12.7%. 产物结构用IR, 1H NMR, 13C NMR, MS 和元素分析进行了表征, 对影响反应的因素进行了讨论. 相似文献
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Highly efficient and selective syntheses of the title compounds are described. The cornerstone of the synthetic plan is the tandem inter [4 + 2]/inter [3 + 2] cycloaddition process. These syntheses differ from previous applications of this strategy in that they incorporate an alkylation in the hydrogenolysis step to close the second ring of the azabicyclic systems. Notable features of the sequence are (1) the highly regio- and stereoselective [3 + 2] cycloaddition of nitronate 15 with siloxymethyl (Z)-beta-silylvinyl ketone (Z)-22b and (2) the highly selective reduction of the resulting ketone 24a with L-Selectride. A single-crystal X-ray structure analysis of synthetic (-)-7-epiaustraline confirmed that the targeted structure was successfully synthesized. This stimulated a reexamination of the structural assignment of the natural product. (-)-1-Epicastanospermine was synthesized in four steps from the common intermediate 27a. The absolute configuration of (-)-1-epicastanospermine was assured by single-crystal X-ray structure analysis of intermediate (-)-27a. Thus, the sign of the optical rotation had to be revised. The overall efficiency of these syntheses were 9 steps and 23% yield for (-)-7-epiaustraline and 10 steps and 20% yield for (-)-1-epicastanospermine 相似文献
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由L-氨基酸不对称合成了4种新型手性化合物(6a,6b,7a,7b),其结构经IR,~1H NMR,~(13)C NMR及MS等证实。 相似文献
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The nitro group in 1-(pentafluorophenyl)-2-nitroalkanols is reduced selectively to a hydroxylamino or amino group by controlled potential electrochemical reduction. The pentafluoro-phenylaminoalkanols cyclize readily on heating in dimethylformamide to give homologs of 4,5,6,7-tetrafluoroindole. It is shown that the intermediate in the cyclization of 1-pentafluorophenyl-2-aminoethanol is 3-hydroxy-4,5,6,7-tetrafluoroindoline. Cyclization of 1-pentafluorophenyl-2-hydroxyaminoethanol gave 1,3 -dihydroxy-4,5,6,7-tetrafluoroindoline.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 5, pp. 622–625, May, 1970. 相似文献
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Ya. V. Ogle L. Kh. Baumane Ya. P. Stradyn' G. Ya. Dubur V. P. Kadysh R. A. Gavar V. K. Lusis 《Chemistry of Heterocyclic Compounds》1985,21(8):917-923
The potentials of the electrolytic oxidation and reduction of 3,5-diethoxycarbonyl- 1,2- and -1,4-dihydropyridines with a nitroaryl substituent in the 4 position and their oxidized forms were determined by the method of a rotating disk electrode with a ring. The mechanism of the electrochemical oxidation of the starting dihydropyridines in acetonitrile on a graphite electrode was ascertained. The first step in the electrolytic reduction of the starting dihydropyridines is the addition of an electron to the nitro group to give anion radicals, the fine electronic structures and the hyperfine structure (hfs) constants of which were determined by EPR spectroscopy. The pyridinium fragment in the electrolytic oxidation products is reduced more readily than the nitro group in the aryl substituent.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1099–1105, August, 1985. 相似文献
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异氰酸苯醇和N-[2-(4,6-二甲基)-嘧啶基]-羟胺(5)反应生成1-[2-(4,6-二甲基)-嘧啶基]-1-羟基-3-苯基脲(6)。化合物(6)在三乙胺存在下和氯甲酸乙醇反应生成2-[2-(4,6-二甲基)-嘧啶基]-4-苯基-1,2,4-噁二唑烷-3,5-二酮(1)。 相似文献
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相转移催化法合成1-O-酰基-四-O-乙酰基-β-D-吡喃己糖 总被引:10,自引:0,他引:10
以氯化三乙基苄基铵作为相转移催化剂, 用2, 3, 4, 6-四-O-乙酰基-β-D-溴代吡喃葡萄糖和2, 3, 4, 6-四-O-乙酰基-β-D-溴代吡喃半乳糖与羧酸反应, 合成了相应的1-O-酰基-2, 3, 4, 6-四-O-乙酰基-β-D-吡喃葡萄糖和半乳糖。通过解析这些化合物的^1H NMR和红外光谱, 确证其糖甙键构型为β。该相转移催化法具有反应条件温和, 后处理简单和立体选择性强等优点。 相似文献
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A diastereoselective and modular approach to the synthesis of the 3-hydroxymethyl-2,3,5,6,7,7a-hexahydro-1H-pyrrolizine-1,2,7-triol structure, characteristic of several natural pyrrolizidine natural products, has been developed. This approach culminated in the synthesis of (-)-7-epiaustraline and (+)-1,7-diepiaustraline. The oxazolidinone group has been found to be a useful protecting group in the RCM reaction and, as part of a pyrrolo[1,2-c]oxazol-3-one ring system, has functioned as a stereo- and regio-directing group in a key diastereoselective cis-dihydroxylation reaction and a regioselective nucleophilic ring-opening of a S,S-dioxo-dioxathiole. 相似文献