首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
3.
4.
The authors describe the synthesis of decahydro-4-quinolinones and N-substituted 4-alkynyl-, 4-allyl- and 4-alkyldecahydro-4-quinolinols and discuss the stereochemical problems of this compounds.  相似文献   

5.
Preparation of the tetrahydroisoquinolin-4-ols indicated in the title and their oxidation by different reagents (chromic anhydride, NBA, dimethylsulfoxide, Oppenauer oxidation) is reported. Only the last reaction led to the title compounds, while the other reagents (except NBA) yielded 1,2,3-trioxotetrahydroisoquinoline. Furthermore, the reactivity of 6,7-dimethoxytetrahydroisoquinolin-4-one was examined towards different carbonyl reagents.  相似文献   

6.
Molecular ionization potentials for series of compounds of the type X? C6H4? CN, X? C6H4CH2? CN and X? C6H4? N(CH3)2 have been measured using the retarding potential difference technique (RPD. technique). The effect of the various substituents X is better correlated through the electrophilic Brown σp+ constants than through Hammett's σp values. No meta-para orientation effect is observed. For all the disubstituted phenyl compounds studied, the effect of the second substituent is affected by the electron-releasing power of the original substituent. Ionization potentials calculated by using the semi-empirical method of equivalent orbitals are in good agreement with the experimental values.  相似文献   

7.
The adduct 1,4-benzoquine · TiCl4 has been prepared in CH2Cl2 solution at about ?60°. Its IR. spectrum has been recorded at the same temperature. The experimental study of the vibrational frequencies has been completed by the calculation of the fundamental vibrations in the molecular plane, using Wilson's FG method, with slightly simplified models of 1,4-benzoquinone · TiCl4 (13 masses) and 1,4-benzoquinone · 2 TiCl4 (14 masses); analysis by use of internal and symmetry coordinates. An assignment of most of the observed bands is proposed and the conclusion is reached that the complex, when solid, is (1,4-benzoquinone · TiCl4)n. The force constants F(C? O) are 9,85 · 105 dyne/cm for the quinone and 8,8 · 105 dyne/cm for the disturbed carbonyl bond of the polymerized complex in the model proposed. At ordinary temperature in benzene solution of the components the adduct 1,4-benzoquinone. TiCl4 · benzene precipitated; with the help of the models, the fundamental vibrations of its IR. spectrum have been assigned.  相似文献   

8.
9.
Enantiospecific Synthesis of (+)-(R)-6-Ethyl-2,3-dihydro-2-methyl-4H-pyran-4-one, Sex-pheromonal Component of the Male Swift Moth Hepialus hecta L . A new synthesis of (+)?(R)-6-ethyl-2,3-dihydro-2-methyl-4H-pyran-4-one ((R)- 8 ), sex-pheromonal component of the male swift moth Hepialus hecta L., has been performed from (?)-(R)-1-(1,3-dithian-2-yl)propan-2-ol with an enantiomeric excess of ? 97%.  相似文献   

10.
A gas-chromatographic investigation of black tea aroma has revealed, besides 19 known components, the presence of 4 new substances: 1-penten-3-ol, trans-2-hexen-1-ol, α-terpineol and β-ionone. The fragmentation pattern of 1-penten-3-ol has been determined by means of high resolution mass spectrography.  相似文献   

11.
The Synthesis of some 4-Nitroisoxazoles from Pseudonitrosites of Chalcones The action of dinitrogen trioxide with α,β-unsaturated ketones of the chalcone type leads to pseudonitrosites (Table 1) which are cyclized to 4-nitro-3,5-diarylisoxazoles (Table 2).  相似文献   

12.
The mass spectra of three δ-functionalized alkynes provide evidence for the migration of chlorine, bromine and hydroxyl towards the unsaturated portion of the molecules. The strong resemblance between these spectra and those of the isomeric allenes suggests that an acetylene→allene isomerization occurs after electron impact.  相似文献   

13.
14.
15.
The Lewis acid isomerisation of a dioxaspirodecanol mixture, obtained by photochemical means, preferentially gives the cis isomer while acetylation mainly leads to the trans isomer. The theromolysis of the acetates 2 or the xanthates 5 yields a furan compound 4, enventual precursor of a dioxaspirolactone. 6. The xanthate reduction provides an easy access to th e methyl-4 dioxaspirodecane isomers of wasp pheromones.  相似文献   

16.
Acetylenic amindines HC≈?C·(CH2)n·C(?NH)NH2 give, by condensation with β-ketoesters, pyrimidones substituted on carbon 2 by an acetylenic chain. Two types of evolution are observed when compounds are heated without any catalyst. The minor route is a cyclization by attack on a triple bond by the amidic nitrogen atom. The main reaction is a cycloaddition involving the non activated triple bond and an azadienic system, leading to non isolated tricyclic intermediates which retrocyclize to stable bicyclic compounds.  相似文献   

17.
The nmr and ir spectra show that Schiff bases of 4-acylisoxazolin-5-ones exist as chelated enaminones type forms. The effects of steric factors on such structures are discussed.  相似文献   

18.
19.
20.
Note on some complexes between nikethamide and/or pemoline with various salts, especially calcium aminoalkylphosphates A number of binary and ternary complexes of nikethamide and/or pemoline with various calcium salts, particularly calcium aminoalkylphosphates, have been prepared in order to assess their pharmacological properties. The formation of such complexes has been established by IR. spectroscopy.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号