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1.
The indole alkaloid norfluorocurarine was reacted with phenylhydrazine. An x-ray crystal structure analysis found that the phenylhydrazine was bonded through its N atoms to C2 and C17 and that the N1–C2 bond of the indole core was cleaved to form an NH2 group and a water molecule was released.  相似文献   

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Transformation products of the alkaloid (–)-norfluorocurarine with hydroxylamine were studied. The oxime of norfluorocurarine was obtained and converted by treatment with EtOH into 2-hydroxy-16-cyano-2,16dihydronorfluorocurarine. The structures of 2-hydroxy-16-cyano-2,16-dihydronorfluorocurarine and 16-cyanonorfluorocurarine hydrochloride were established by XSA and NMR spectroscopy. The absolute structure of 2-hydroxy-16-cyano-2,16-dihydronorfluorocurarine was established and enabled the configurations of the asymmetric centers to be determined as 2R, 3S, 7R, 15S, and 16R.  相似文献   

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The bisindole compound 2β,16α,2′β,16′β(H)-tetrahydronordihydrotoxiferine consisting of two diastereoisomeric deoxytetrahydronorfluorocurarine moieties was isolated from the reduction mixture of the alkaloid norfluorocurarine. 16-Deformyl-2,16,17,20-tetrahydro-20,21-dehydronorfluorocurarine was produced by dehydrogenation of norfluorocurarine; N(β)-methyldihydrodefluorocurarine, by hydrogenation of fluorocurarine. The structures of the synthesized compounds were established by x-ray structure analyses. The configurations of the asymmetric centers in 2β,16α,2′β,16′β(H)-tetrahydronordihydrotoxiferine were determined as 2S,3S,7R,15S,16R,2′S,3′S,7′R,15′S,16′S. Inversion to the R-configuration at the C15 center was observed in N(β)-methyldihydrodefluorocurarine whereas the configurations 3S and 7R were retained. Atom C2 adopted the S-configuration in 16-deformyl-2,16,17,20-tetrahydro-20,21-dehydronorfluorocurarine.  相似文献   

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The syntheses of a variety of fluorine-containing adamantane derivatives are described. The 13C NMR spectra of those compounds with different configurations are interpreted in terms of through-bond and through-space substituent interactions.  相似文献   

6.
Structures of the alkaloids (−)-norfluorocurarine, its racemate (±)-norfluorocurarine from Vinca erecta, and fluorocurarine obtained by N(β)-methylation of (−)-norfluorocurarine were established by x-ray crystal structure analyses. The alkaloid crystallized with two molecules in the asymmetric unit for the first two crystals. The asymmetric unit of (±)-norfluorocurarine crystal consisted of two antipods. The asymmetric unit in the crystal of the last compound consisted of the N(β)-methylated cation and a hydroxide anion. The formation of bimolecular associates through intermolecular N–H…O H-bonds was typical of these crystal- line structures. An associate in the crystal structure of fluorocurarine involved two hydroxide anions.  相似文献   

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Conclusions The NMR spectra of nine coumarin derivatives have been studied. The results obtained may be used for purposes of structural analysis.Khimiya Prirodnykh Soedinenii, Vol. 6, No. 1, pp. 6–14, 1970  相似文献   

10.
Chemistry of Natural Compounds - The NMR spectra of nine coumarin derivatives have been studied. The results obtained may be used for purposes of structural analysis.  相似文献   

11.
The fluorine chemical shifts and spin-spin coupling constants of 65 pentafluorophenyl derivatives with widely varying organic substituents were examined. Useful correlations of the three meta coupling constants with the chemical shifts of the para fluorine were found. It is suggested that these relationships be extended to all compounds of the type considered in order to determine the signs and approximate values of meta coupling constants. Equations for correlation of the fluorine chemical shifts with the Taft constants are presented. The possibility of calculating the Taft constants from the 19F NMR spectra of pentafluorophenyl compounds is being discussed.  相似文献   

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The carbon-13 chemical shifts of mono- and 1,3-disubstituted adamantanes are reported. The effects caused by the substituents are compared with those met in aliphatic and alicyclic compounds. It is shown that the 1,4-interactions have only minor importance in l-substituted adamantanes. The influence of polar groups on the chemical shifts of γ- and δ-carbon atoms is a typical ‘through-the-bonds’ interaction and correlates with inductive parameters of the substituents.  相似文献   

17.
Conclusions A series of derivatives of furan and tetrahydrofuran were synthesized on the basis of 5-methylfurfural: alkyl(5-methylfuryl)carbinols, alkyl(5-methyltetrahydrofuryl)carbinols, 2-methyl-5-alkenylfurans, 2-methyl-5-alkylfurans, and 2-methyl-5-alkyltetrahydrofurans.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 1829–1831, October 1966.  相似文献   

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4,6-Dihydroxy-5-acetylpyrimidine was obtained by the solvolysis of 4,6-dialkoxy-5-acetylpyrimidines. The hydrolysis of 4,6-dichloro-5-acetylpyrimidine leads to opening of the heteroring to give s-cis,trans conformera of 2-cyano-3-hydroxy-2-buteneamide. 2,4,6-Trihydroxy[4,5]bipyrimidine was obtained by the condensation of 4,6-dialkoxy-5-acetylpyrimidines with benzalbisurea. It is shown that the products of the reaction of the same ketones with benzaldehyde in the presence of sodium alkoxides are derivatives of -diketones.See [1] for Communication 74.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 378–385, March, 1985.  相似文献   

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