共查询到19条相似文献,搜索用时 218 毫秒
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雌甾-11-酮化合物是合成11-烃基取代甾体化合物的关键中间体。文献多采用硼氢化-过氧化氢氧化得11α-羟基物,再经进一步氧化得雌甾-11-酮化合物。两步反应均有副产物生成,总收率很低(31%)。Brown 等报道有机硼烷化合物用重铬酸钠的硫酸水溶液氧化可直接得到酮。我们将此 相似文献
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手性3-溴-2(5H)-呋喃酮的合成及其串联的不对称Michael加成 反应的研究 总被引:2,自引:0,他引:2
研究了新的手性试剂,5-(l-孟氧基)-3-溴-呋喃酮(5a)的合成及其与亲核性醇发生的串联不对称双Michael加成/分子内亲取代反应。通过此反应,一举生成了四个新的手性中心,得到了一般方法难以合成的含有多个手性中心的丁内酯并螺-环丙烷类化合物8a~8d。详细报道了8a~8d的合成方法以及它们的[α]、IR、UV、^1^HNMR、^13^CNMR、MS、元素分析等结构分析数据。此不对称双Michael加成/分子内亲核取代反应可以为某些新的光学活性螺-环内丙烷类化合物以及某些复杂结构的分子提供合成策略。 相似文献
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为了发展转变点温度(Tc)高的有机磁性分子,设计合成了4,5-四硫富瓦烯-双(2,3,6,7-二苯基-氮杂环庚烷-1-氧化物)。反应混合物均经硅胶柱和设备HPLC分离和纯化,产物的结构由MS、^1^HNMR、^1^3CNMR等确定。 相似文献
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The 1H, 31P, and 13C NMR parameters of 1,3,2-benzoxazaphosphorin-4-one derivatives I [R = heterocyclyl; R1 = OEt, NMe2, (ClCH2CH2)2N, (ICH2CH2)2N; X = O, S] have been studied. Effects of chiral phosphorus atom on 1H spectra of these compounds are discussed. 相似文献
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利用无水碳酸钾作缩合剂,在精制乙腈中使N,N'-二对甲苯磺酰基-1,4,7-三氮杂环壬烷3与双溴甲基化合物4a-4c缩合得到N-对甲苯磺酰基取代的桥连双-(三氮杂环壬烷)5a-5c,经浓硫酸脱去氮原子上的保护基团得到桥连双-(三氮杂环壬烷)6a-6c。化合物5a-5c和6a-6c均经元素分析、IR、^1HNMR、^1^3CNMR、MS等测试手段证实其结构和组成。 相似文献
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P. F. Vlad D. P. Popa E. C. Gorincioi M. N. Coltsa G. N. Mironov 《Russian Chemical Bulletin》2000,49(1):98-101
A synthetic route to 11-hydroxydrim-8(9)-en-7-one and 11,12-hydroxydrim-8(9)-en-7-one, valuable key intermediates for the
preparation of naturally occurring biologically active drimanic sesquiterpenoids, starting from easily available drim-8(9)-en-7-one
was developed. 11-Hydroxydrim-8(9)-en-7-one was obtained by peracidic oxidation of the enol acetate of drim-8(9)-en-7-one.
11,12-Dihydroxydrim-8(9)-en-7-one was synthesized from drim-8(9)-en-7-one by two routes, namely, by a five-step procedurevia 11-hydroxydrim-8(9)-en-7-one and by bromination of drim-8(9)-en-7-one with NBS to give 11,12-dibromodrim-8(9)-en-7-one followed
by its acetoxylation and deacetylation.
Deceased
Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 95–98, January, 2000. 相似文献
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P. F. Vlad D. P. Popa E. C. Gorincioi M. N. Coltsa G. N. Mironov 《Russian Chemical Bulletin》1990,49(1):98-101
A synthetic route to 11-hydroxydrim-8(9)-en-7-one and 11,12-hydroxydrim-8(9)-en-7-one, valuable key intermediates for the
preparation of naturally occurring biologically active drimanic sesquiterpenoids, starting from easily available drim-8(9)-en-7-one
was developed. 11-Hydroxydrim-8(9)-en-7-one was obtained by peracidic oxidation of the enol acetate of drim-8(9)-en-7-one.
11,12-Dihydroxydrim-8(9)-en-7-one was synthesized from drim-8(9)-en-7-one by two routes, namely, by a five-step procedurevia 11-hydroxydrim-8(9)-en-7-one and by bromination of drim-8(9)-en-7-one with NBS to give 11,12-dibromodrim-8(9)-en-7-one followed
by its acetoxylation and deacetylation.
Deceased
Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 95–98, January, 2000. 相似文献
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The kinetics of oxidation of tartaric acid by Ce(IV) in the absence and presence of acrylamide has been investigated spectrophotometrically in aqueous H2SO4–HClO4 media at a constant ionic strength 2.0M and 25°C. Oxidation of tartaric acid in both cases was first order with respect to Ce(IV). Kinetic data showed that the reaction involves the formation of an unstable complex and an intermediate free radical. The activation parameters were calculated to be E
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=91.3±0.4 kJ-mol–1, S=20.2±1.0 J-mol–1-K–1, H=88.8±0.4 kJ-mol–1. A polymerization mechanism is discussed. 相似文献
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碘化10-乙羧基吖啶-9-羧酸苯酯的电致化学发光行为研究 总被引:3,自引:0,他引:3
研究了碘化10-乙羧基吖啶-9-羧酸苯酯(CACPEI)的电致化学发光行为.结果表明,在KNO3介质中,于Pt电极上施加正矩形脉冲电压时,10-乙羧基吖啶-9-羧酸苯酯产生很强的电致化学发光(ECL)信号,信号强弱受电化学参数和发光反应条件的影响,探讨了可能的发光机理.在最佳条件下发光信号与CACPEI的浓度在5.0×10-10~1.2×10-7g/mL范围内呈良好的线性关系.检出限可达2.4×10-10g/mL. 相似文献
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K. I. Kuchkova A. N. Aryku I. P. Dragalin P. F. Vlad 《Chemistry of Natural Compounds》2005,41(2):190-193
Drim-9(11)-en-8α-ol and drim-9(11)-en-8β-ol were synthesized in six steps from drimenol. Drimenol was oxidized by P2O5 and DMSO to drimenal, which isomerized with p-TsOH into isodrimenal. Isodrimenal was reduced by NaBH4 into isodrimenol, epoxidation of which by m-CPBA gave a mixture (3.4:1) of α- and β-epoxyisodrimenols. These reacted with tosyl chloride in Py to give a mixture of α- and β-epoxyisodrimenol tosylates. Treatment of the tosylate mixture with KI and then Ph3P produced a mixture of drim-9(11)-en-8α- and -8β-ols that was separated chromatographically. The overall yield was ∼26%.__________Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 152–155, March–April, 2005. 相似文献
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The kinetics of ruthenium(III)-catalyzed oxidation of several arylthioacetic acids by Ce(IV) have been studied. The proposed
mechanism involves the formation of a 1∶1 complex between Ru(III) and arylthioacetic acid, which then reacts with Ce(IV). 相似文献
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Shigekazu Yamazaki 《合成通讯》2013,43(17):2210-2218
4,4′-Dicarboxy-2,2′-bipyridine was synthesized quantitatively by chromium(VI) oxide-mediated oxidation of 4,4′-dimethyl-2,2′-bipyridine or 4,4′-diethyl-2,2′-bipyridine with periodic acid as the terminal oxidant in sulfuric acid. 5,5′-Dicarboxy-2,2′-bipyridine and 6,6’-dicarboxy-2,2′-bipyridine were also synthesized by the method from the corresponding dimethyl bipyridines in excellent yields. 4,4′,4″-Tricarboxy-2,2′:6′,2″-terpyridine was obtained in 80% yield from 4,4′,4″-triethyl-2,2′:6′,2″-terpyridine, and 4,4′,4″,4′″-tetracarboxy-2,2′:6′,2″:6″,2′″-quaterpyridine was obtained in 72% yield from 4,4′,4″,4′″-tetraethyl-2,2′:6′,2″:6″,2′″-quaterpyridine by the same procedure. 相似文献