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1.
Synthesis of Sugar Derivatives Bearing a Spiro Heterocycle via Nucleophilic Cyclization Treated with the 1,4-binucleophiles 1,2-diaminoethane, 2-aminoethanol, 2-aminoethanethiol, L -cysteine, o-phenylenediamine, o-aminophenol or o-aminothiophenol the ketosugar derivative 1 gave in good yields the corresponding spiro derivatives 2–8 . In each case, the reaction was stereospecific leading to the isomer bearing the N-atom on the endo face of the bicyclic starting material. Starting from the sugar enone 9 , the aromatic 1,4-binucleophiles led stereospecifically to the spirobenzo [b]-diazepine 10 , -oxazepine 11 or -thiazepine 12 . In one case, an imine (13) was isolated. As 13 cyclized to 6 , the intermediate formation of these kind of derivatives could be considered as a common step for all these reactions. 相似文献
2.
The mass spectra of a series of imidazo[4,5,1-jk]1,4-benzodiazepines and imidazo[1,5,4-ef]1,5-benzodiazepines have been examined. The differences in the fragmentation patterns permit the isomeric structures to be identified. 相似文献
3.
Jean-Paul Affane-Nguema Jean-Pierre Lavergne Philippe Viallefont 《Journal of mass spectrometry : JMS》1977,12(3):136-144
The mass spectra of 21 1,4-pyrazolo[3,4-b]diazepines are reported and analysed. Each of the five structures of the diazepine ring present is characterized by a particular group of fragmentations; among them one is common to all the compounds under study: the cleavage of C-5? C-6 and C-7? N-8 bonds leading to pyrazoloimidazoles ions. 相似文献
4.
Synthesis of Eriodermin The total synthesis of eriodermin (=2,7-dichloro-4-formyl 3-hydroxy-8-methoxy-1,6-dimethyl-11H-dibenzo[b,e] [1,4]dioxepin-11-one) is described. 相似文献
5.
Synthesis of Methyl Virensate The synthesis of methyl virensate (=methyl 4-formyl-3,8-dihydroxy-1,6,9-trimethyl-11-oxo-11H-dibenzo-[b, e][1,4]dioxepin-7-carboxylate; 18 ) by the condensation of the substituted β-orcinol and orcinol units 9 and 10 followed by formylation and demethylation of the depsidone 13 is described. 相似文献
6.
We report here a one-step synthesis of the 4,5,6,7-tetrahydro-1H- 1,2,4,-triazolo[4,3-d][1,4]diazepine, 4-6, and 1,2,4-oxadiazolo[4,5-d][1,4]-diazepine, 7-10, by 1,3-dipolar cycloaddition of nitrile imines and nitrile oxides with 2,3-dihydro-H-1,4-diazepine, 1. In all cases these cycloaddition are peri- and regioselectives (the C ? N bond is sole affected) and occures with high yields. Structure and conformations of cycloadducts have been assigned by means of nmr analysis 相似文献
7.
Alain Essel Quang Tho Pham 《Journal of polymer science. Part A, Polymer chemistry》1972,10(9):2793-2801
With accumulated HR-NMR spectra of anionic polyisoprenes, it has been possible to study the influence of the nature of the propagating species on the microstructure of the obtained polymers If free ions are responsible for the propagation, the microstructure (1,4-: 25%, 1,2-: 33%, 3,4-: 42%) does not depend on the nature of the cations. But with contact ion pairs, the different addition modes are governed by the size of the alkali metal counterions. Mechanisms of anionic propagations via diene–cation coordination are proposed. 相似文献
8.
Michel Pfau Ned D. Heindel Fazil O. Gülaar Armand Buchs 《Journal of mass spectrometry : JMS》1977,12(10):644-650
The 70 eV electron impact mass spectra of a series of substituted 1-phenylnaphthalenes and their corresponding 1,4-dihydro-1-naphthols have been studied. Plausible fragmentation modes which account for the formation of all the major ions are proposed. An interesting hydrogen transfer reaction, leading to major fragments through the elimination of methanol, seems to proceed via an 8-membered transition state mechanism. 相似文献
9.
Cycloaddition of 1,3-diphenyl-2-azaallyllithium to tolane, diphenylbutadiyne and 1,4-diphenylbutenyne E produces quantitatively 2,3,4,5-tetraphenylpyrrole, 3-phenylethynyl-2,4,5-triphenyl-3-pyrroline and 3-phenylethynyl-2,4,5-triphenylpyrrolidine, respectively. Treatment before hydrolysis with benzyl bromide or dimethl sulfide gives N-alkyl-substituted derivatives. The structure of 3-pyrrolines was established by spectral data and chemical correlations. Stereochemical courses of this new synthetic method for 3-pyrrolines are discussed. 相似文献
10.
Jacques Dagaut Michele Ricard Jean Pierre Brun Danielle Leblanc 《Journal of mass spectrometry : JMS》1977,12(7):445-452
The existence of different isomers of phenyl benzocyclobutene derivatives of specifically deuterium labelled 1,4-benzodioxin molecular ions have been demonstrated. The number of differently labelled benzoyl and formyl radicals being lost facilitated the determination of the relative importance of the various molecular ion isomers. 相似文献
11.
Study of acylation of 3-acetyl-8-acetoxyindolizine by miscellaneous acid chlorides in the presence of aluminium chloride shows that this reaction is either limited to a transesterification (in the case of benzoyl chloride) or leads to introduction of an acyl group in position 1 with simultaneous liberation of the phenol function in position 8. When acylation takes place, acetyl chloride resulting from the cleavage of the acetoxy group competes with the acid chloride used in the reaction. Predominant acylation by the latter is observed when the reaction is performed with ethoxalyl chloride or with non branched aliphatic acid chlorides; by contrast solely acetylation takes place when pivaloyl or phenylacetyl chloride is used. These results are tentatively explained by a process related to the Fries rearrangement. The hypothesis of intramolecular transfer of an acyl group from the ester function in position 8 can be discarded by the observed results. 相似文献
12.
J.-P. Affane-Nguema J.-P. Lavergne Ph. Viallefont 《Journal of heterocyclic chemistry》1977,14(3):391-395
Condensation of ethyl acetoacetate or acetylacetone with 4,5-diaminopyrazoles are reported and discussed. They gave new pyrazolo[3,4-b]-1,4-diazepines or intermediates which can be cyclised. 相似文献
13.
A cyclisation of 1-bromo-5,5,10,10-tetraethoxycarbonyl-2,7-decadiyne ( 9b ) using NaH in dilute solution gives 1,1,6,6-tetraethoxycarbonyl-cyclodeca-3,8-diyne ( 8 ) in 17,6% yield. 9b is prepared by condensation of 1,1,6,6-tetraethoxycarbonyl-3-hexyne with 1,4-dibromo-2-butyne. 相似文献
14.
Electrochemical reduction of [1]benzopyranno[4,3-e]-as-triazinones gives 1,4-dihydro derivatives which can either rearrange into 4,4a-dihydro compounds or be reduced with ring contraction into benzopyranno-imidazolones. The reaction of Grignard reagents on benzopyrannotriazines leads to a reduction in –α position of the benzene ring (4,4a-dihydro). Electrochemical reduction gives the 1,4-dihydro derivative which rearrange into the 1,10a-dihydro compound. The 1,4-dihydro derivatives are reduced with triazine ring contraction to give benzopyrannoimidazoles. Dihydro-1,10a compounds can be reduced into imidazoles or into tetrahydro derivatives. 相似文献
15.
J. Pornet 《Journal of organometallic chemistry》1988,340(3):273-282
Alkyl -substituted 1,4-bis(trimethylsilyl)-2-alkynes react with electrophilic reagents to give silylated conjugated dienes, which result from a 1,2-shift of a trimethylsilyl group to a vinylic cationic center. 相似文献
16.
Studies of Organometallic Compounds, XX. Selectivity of 1,4-Addition of Benzyltitanium Compounds with Benzylildenacetone Tetrabenzyltitanium and dialkoxydibenzyltitanium compounds give essentially 1,4- addition with trans-4-phenyl-3-buten-2-one. 相似文献
17.
Nucleophilic aromatic substitution of 3-bromo-2nitrothiophene and selenophene by thiocyanate and selenocyanate ions in dimethylsulfoxide yields 3-thienyl-and 3-selenienylthicoyanates and selenocyanates. After reduction of the nitro group, the amino derivatives undergo cyclizatrion to thieno[2,3-d]thiazoles and seleno [2,3-d]thiazoles. Also, 4H-2,3-dihydro-3-oxothieno[2,3-e]1,4-thiazine and its selenophene analog have been obtained. 相似文献
18.
Starting from 2-methyl- and from 2,3-dimethyl-1,4-diphenyl-butadiene-1, 3 respectively, the 5-methyl- and the 5,6-dimethyl-11, 12-dihydro-indeno[2.1-a]fluorene are synthesized in 4 steps. The 5, 6-diphenyl-11, 12-dihydro-indeno[2.1-a]fluorene is obtained by reduction of the already known 11, 12-dioxoderivative. Accesorily a new preparation of the unsubstituted hydrocarbon is described. 相似文献
19.
20.
X-ray studies indicate that indanone-1 crystals belong to a monoclinic system, space group P21/c (C52h), with the following parameters: a = 7.90±0.01 Å; b = 12.38±0.01 Å; c = 7.39±0.01 Å; β = 99°±30' and Z = 4. A vibrational assignment of fundamental bands observed in the polarized infrared spectrum between 4000 cm−1 and 250 cm−1 is proposed. The band fine structure analysis at 77 °K shows a doublet structure, which agrees with X-ray data. 相似文献