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Summary 1. The reduction of 3-methoxy-D-homoestra-1, 3, 5(10), 8-tetraen-17a-ol (IV) with alkali metals in the presence of ammonium chloride or alcohol gives, in addition to 8, 9-dihydro derivatives, the 8, 9 and 8, 9-epimers, the structure of which has been shown partly by independent synthesis and partly on the basis of chemical reactions and NMR spectra.2. Hydrolysis of the reduction products has given 19-nor-D-homotestosterone (III) and its 8- and 9, 10-epimers (V) and (VI). The ketols (III) and (V) readily form hydroperoxides in air.3. The reduction of the ethylene ketal of 3-methoxy-D-homoestra-1, 3, 5(10), 8-tetraen-17a-one (XIX) takes place stereodirectively and gives only 8, 9-dihydro derivatives.Khimiya Prirodnykh Soedinenii, Vol. 1, No. 2, pp. 90–100, 1965 相似文献
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《Comptes Rendus Chimie》2014,17(9):952-957
In water, Al powder becomes a powerful reducing agent, transforming in cyclohexyl either one or both benzene rings of aromatic compounds such as biphenyl, fluorene and 9,10-dihydroanthracene under mild reaction conditions in the presence of noble metal catalysts, such as Pd/C, Rh/C, Pt/C, or Ru/C. The reaction is carried out in a sealed tube, without the use of any organic solvent, at low temperature. Partial aromatic ring reduction was observed when using Pd/C, the reaction conditions being 24 h and 60 °C. The complete reduction process of both aromatic rings required 12 h and 80 °C with Al powder in the presence of Pt/C. 相似文献
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N. V. Volchkov A. V. Zabolotskikh M. B. Lipkind O. M. Nefedov 《Russian Chemical Bulletin》1989,38(8):1782-1782
Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, p. 1935, August, 1989. 相似文献
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V. A. Mamedov E. A. Berdnikov I. A. Litvinov L. G. Kuz'mina 《Russian Chemical Bulletin》1995,44(7):1247-1251
3,3-Dichloropentane-2,4-dione reacts with aromatic aldehydes under the conditions of Darzens reaction to give 4-acetoxy-4-aryl-3,3-dichlorobutan-2-ones, the products of insertion into the -C-C bond. The reaction of ethyl dichloroacetylacetate with benzaldehyde yields a derivative of tricyclo[5.1.0.03,5]octane, rather than 2,6-bis(1-chlorobenzylidene)cyclohexane-1,4-dione, as the by-product.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1294–1298, July, 1995. 相似文献
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V. Sh. Shaikhrazieva E. V. Tal'vinskii L. M. Khalilov G. A. Tolstikov 《Russian Chemical Bulletin》1979,28(2):371-374
Conclusions The photoreaction of dichloromaleimide with benzene, fluorobenzene, and anisole has been investigated. In the first two cases, the main process comprises the 1,2-addition of two dienophile molecules. The reaction with anisole proceeds exclusively by a scheme comprising substitution to form anisylmaleimides followed by photodimerization.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 401–404, February, 1979. 相似文献
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Gil Zilber Vladimir Rozenshtein Ari Ayalon Haim Levanon Mordecal Rabinovitz Lawrence T. Scott Hope B. Warren Gaby Persy Jakob Wirz 《Research on Chemical Intermediates》1996,22(9):839-854
Five reaction stages have been identified in the reduction of pyracylene to its dianion. The same stages were also observed in the photochemical oxidation starting with the dianion. The formation of dimers of anions and of mixed valence aggregates is discussed. 相似文献
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The secondary formation of HO(2) radicals following OH + aromatic hydrocarbon reactions in synthetic air under normal pressure and temperature was investigated in the absence of NO after pulsed production of OH radicals. OH and HO(x) (=OH + HO(2)) decay curves were recorded using laser-induced fluorescence after gas-expansion. The prompt HO(2) yields (HO(2) formed without preceding NO reactions) were determined by comparison to results obtained with CO as a reference compound. This approach was recently introduced and applied to the OH + benzene reaction and was extended here for a number of monocyclic aromatic hydrocarbons. The measured HO(2) formation yields are as follows: toluene, 0.42 ± 0.11; ethylbenzene, 0.53 ± 0.10; o-xylene, 0.41 ± 0.08; m-xylene, 0.27 ± 0.06; p-xylene, 0.40 ± 0.09; 1,2,3-trimethylbenzene, 0.31 ± 0.06; 1,2,4-trimethylbenzene, 0.37 ± 0.09; 1,3,5-trimethylbenzene, 0.29 ± 0.08; hexamethylbenzene, 0.32 ± 0.08; phenol, 0.89 ± 0.29; o-cresol, 0.87 ± 0.29; 2,5-dimethylphenol, 0.72 ± 0.12; 2,4,6-trimethylphenol, 0.45 ± 0.13. For the alkylbenzenes HO(2) is the proposed coproduct of phenols, epoxides, and possibly oxepins formed in secondary reactions with O(2). In most product studies the only quantified coproducts were phenols whereas only a few studies reported yields of epoxides. Oxepins have not been observed so far. Together with the yields of phenols from other studies, the HO(2) yields determined in this work set an upper limit to the combined yields of epoxides and oxepins that was found to be significant (≤0.3) for all investigated alkylbenzenes except m-xylene. For the hydroxybenzenes the currently proposed HO(2) coproducts are dihydroxybenzenes. For phenol and o-cresol the determined HO(2) yields are matching the previously reported dihydroxybenzene yields, indicating that these are the only HO(2) forming reaction channels. For 2,5-dimethylphenol and 2,4,6-trimethylphenol no complementary product studies are available. 相似文献
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I2负载蒙脱土超声法催化Biginelli反应 总被引:1,自引:0,他引:1
以芳香醛、乙酰乙酸乙酯及脲为原料,I2负载蒙脱土为催化剂,对超声条件下Biginelli反应进行研究。用单因素法考察溶剂及催化剂对产率的影响,通过正交试验优化温度、超声时间及原料摩尔比。优化反应条件为:反应温度80℃,超声时间5min,芳香醛、乙酰乙酸乙酯和脲的摩尔比为1∶1∶1,催化剂用量为10(mol)%,产率最高可达86.9%。合成的7种3,4-二氢嘧啶-2(1H)-酮衍生物的结构通过红外光谱、核磁共振氢谱和熔点进行表征。 相似文献
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The temperature dependence of the rate coefficients for the OH radical reactions with toluene, benzene, o-cresol, m-cresol, p-cresol, phenol, and benzaldehyde were measured by the competitive technique under simulated atmospheric conditions over the temperature range 258–373 K. The relative rate coefficients obtained were placed on an absolute basis using evaluated rate coefficients for the corresponding reference compounds. Based on the rate coefficient k(OH + 2,3-dimethylbutane) = 6.2 × 10?12 cm3 molecule?1s?1, independent of temperature, the rate coefficient for toluene kOH = 0.79 × 10?12 exp[(614 ± 114)/T] cm3 molecule?1 s?1 over the temperature range 284–363 K was determined. The following rate coefficients in units of cm3 molecule?1 s?1 were determined relative to the rate coefficient k(OH + 1,3-butadiene) = 1.48 × 10?11 exp(448/T) cm3 molecule?1 s?1: o-cresol; kOH = 9.8 × 10?13 exp[(1166 ± 248)/T]; 301–373 K; p-cresol; kOH = 2.21 × 10?12 exp[(943 ± 449)/T]; 301–373 K; and phenol, kOH = 3.7 × 10?13 exp[(1267 ± 233)/T]; 301–373 K. The rate coefficient for benzaldehyde kOH = 5.32 × 10?12 exp[(243 ± 85)/T], 294–343 K was determined relative to the rate coefficient k(OH + diethyl ether) = 7.3 × 10?12 exp(158/T) cm3 molecule?1 s?1. The data have been compared to the available literature data and where possible evaluated rate coefficients have been deduced or updated. Using the evaluated rate coefficient k(OH + toluene) = 1.59 × 10?12 exp[(396 ± 105)/T] cm3 molecule?1 s?1, 213–363 K, the following rate coefficient for benzene has been determined kOH = 2.58 × 10?12 exp[(?231 ± 84)/T] cm3 molecule?1 s?1 over the temperature range 274–363 K and the rate coefficent for m-cresol, kOH = 5.17 × 10?12 exp[(686 ± 231)/T] cm3 molecule?1 s?1, 299–373 K was determined relative to the evaluated rate coefficient k(OH + o-cresol) = 2.1 × 10?12 exp[(881 ± 356)/T] cm3 molecule?1 s?1. The tropospheric lifetimes of the aromatic compounds studied were calculated relative to that for 1,1,1-triclorethane = 6.3 years at 277 K. The lifetimes range from 6 h for m-cresol to 15.5 days for benzene. © 1995 John Wiley & Sons, Inc. 相似文献
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Ivan N. Bardasov Anastasiya U. Alekseeva Viktor A. Tafeenko Oleg V. Ershov 《Tetrahedron letters》2017,58(42):4003-4005
The synthesis of polycyano-anions, conjugated with an aryl substituent via an ethylene fragment, by the Knoevenagel condensation reaction of aromatic aldehydes with the malononitrile trimer potassium salt is described. 相似文献
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A. S. Kulikov N. N. Makhova T. I. Godovikova S. P. Golova L. I. Khmel'nitskii 《Russian Chemical Bulletin》1994,43(4):630-631
It was shown that the furoxan ring is efficiently reduced to the furazan ring in carbonylsubstituted furoxans with other functional groups by the action of the SnCl2-HC1-AcOH system.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 679–680, April, 1994. 相似文献
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