Reaction of 30-nor-19(20)-lupene derivatives with bromine

1983 ◽  
Vol 48 (12) ◽  
pp. 3444-3454 ◽  
Author(s):  
Eva Klinotová ◽  
Jiří Klinot ◽  
Jiří Protiva ◽  
Jiří Urban ◽  
Alois Vystrčil
Keyword(s):  
Nmr Spectra ◽  
Hydroxy Ketone ◽  
Reaction Conditions ◽  
Unsaturated Alcohols ◽  
C Nmr ◽  
Dibromo Derivative

The reaction of 30-nor-19-lupene-3β,28-diol (I) with bromine gives bromo ether III; from the corresponding diacetate II diene IX, unsaturated alcohols VII and VIII and hydroxy ketone XIV were obtained as products of conversion of the primarily formed dibromo derivative VI, depending on the reaction conditions. The structure and configuration of unsaturated alcohols VII and VIII at C(20) is based on 1H and 13C NMR spectra and the different course of their reaction with peracid.

scholarly journals Boric Acid Catalyzed Convenient Synthesis of Benzimidazoles in Aqueous Media

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Mohammad Reza Poor Heravi ◽  
Marjan Ashori
Keyword(s):  
Boric Acid ◽  
Nmr Spectra ◽  
Aqueous Media ◽  
Reaction Conditions ◽  
Efficient Catalyst ◽  
H Nmr ◽  
Convenient Synthesis ◽  
Ft Ir ◽  
Acid Catalyzed ◽  
C Nmr

Synthesis of benzimidazoles has been developed by theo-phenylenediamine with aldehydes using boric acid an efficient catalyst under mild reaction conditions in aqueous media. The product is applicable to aryl and heteroaryl aldehydes. This reaction led to the formation of benzimidazoles new derivatives in good yields. The FT-IR,19F-NMR,1H-NMR,13C-NMR spectra and elemental analysis confirm the structure of compounds.

scholarly journals Selektive Metallierung von BicycIo[3.2.1]octa-2,6-dien, II Distannylierte Derivate und stannylierte tricyclische Sekundärprodukte / Selective Metalation of Bicyclo[3.2.1]octa-2,6-diene, II Distannylated Derivatives and Stannylated Tricyclic Secondary Products

1988 ◽  
Vol 43 (11) ◽  
pp. 1405-1415 ◽  
Author(s):  
N. Hertkorn ◽  
F. H. Köhler
Keyword(s):  
Nmr Spectroscopy ◽  
Low Temperature ◽  
Nmr Spectra ◽  
Considerable Change ◽  
Coupling Constants ◽  
Secondary Products ◽  
Starting Compound ◽  
Derivatives Of ◽  
C Nmr ◽  
Dibromo Derivative

Abstract Distannylated bicyclo[3.2.1]octa-2,6-diene (1) with (CH3)3 Sn groups in positions exo-4 and 7 (7a), endo-4 and 7 (7b), exo-4 and 6 (7c), and probably exo-4 and endo-4 (7d) are obtained when 1 is treated first with an excess of n-BuLi/t-BuOK in alkane and then with (CH3)3 SnCl. Byproducts are monostannylated derivatives of 1 and l,4-bis(trimethylstannyl)but-2-ene (3). The formation of 7a/b/c is best understood when the two possible bicyclo[3.2.1]octa-2,6-dienyl dianions are generated as intermediates. 3,exo-4-Bis(trimethylstannyl)bicyclo[3.2.1]octa-2,6-diene (7e) is ob-tained from the corresponding dibromo derivative of 1 and (CH3)3SnLi with 3-bromo-exo-4-trimethylstannylbicyclo[3.2.1]octa-2,6-diene (9) as an intermediate. The bicyclic stannyl com-pounds are susceptible to a 1,5-homopentadienyl shift of a (CH3)3Sn group at relatively low temperature when the starting compound has the stannyl group in position 4 of 1 and when positions 6 or 7 are unsubstituted. Tricyclo[3.2.1.02.7]oct-3-enes with (CH3)3Sn groups in positions exo-6 (5a), endo-6 (5b), 3 and exo-6 (10a), and 3 and endo-6 (10b) are thus obtained. On further heating, 10b gives l-trimethylstannyl-3-vinylbenzene (11). All compounds have been studied systematically by NMR spectroscopy including δ(119Sn), δ(13C), δ(1H), 4/5J(119/117Sn-119Sn), nJ(119/117Sn-13C) , nJ(119/117Sn-1H), 1J(13C-1H ) , and nJ(1H-1H ). Among all nuclei, 119Sn gives the most simple spectra. From the 13C NMR spectra a series of useful increments of (CH3)3Sn groups emerges. The most interesting coupling constants are 5J(119/117Sn-119Sn), for which a considerable change with the dihedral angle is established, and nJ(119/117Sn-13C). For n = 3 and 4 the latter are especially useful because their angular dependence leads to unambiguous signal assignments.

Synthesis and NMR Studies of Some Steroidal Isoxazoles

1992 ◽  
Vol 47 (6) ◽  
pp. 891-897 ◽  
Author(s):  
Sergio Giacopello ◽  
Mónica E. Deluca ◽  
Alicia M. Seldes
Keyword(s):  
Nmr Spectra ◽  
Two Dimensional ◽  
Model Compounds ◽  
Nmr Studies ◽  
Reaction Conditions ◽  
Related Model ◽  
H Nmr ◽  
Short Synthesis ◽  
Nmr Methods ◽  
C Nmr

A short synthesis of 17α-pregna-2,4-dien-[2,3-d]isoxazol-17β-ol (1) is described using mild reaction conditions and with a high overall yield. The equilibrium between keto-enolic forms has been studied by 1H NMR methods. Complete assignments of all the resonances in the 1H and 13C NMR spectra of Danazol have been made using a variety of one and two-dimensional correlation methods. 13C NMR spectra of all the intermediate and related model compounds were also assigned.

Structure and Properties of Quaternized 2- and 4-Aminonicotinamides

1995 ◽  
Vol 60 (6) ◽  
pp. 1009-1015
Author(s):  
Svatava Smrčková-Voltrová ◽  
Jaroslav Říha ◽  
Viktor Prutianov
Keyword(s):  
Benzene Ring ◽  
Spectral Properties ◽  
Nmr Spectra ◽  
Electronic Effect ◽  
Structure And Properties ◽  
Reaction Conditions ◽  
Iminium Salts ◽  
Substituted 1 ◽  
Optimal Reaction ◽  
C Nmr

Compounds 2- and 4-aminonicotinamide were quaternized with eight 4-substituted 1-bromomethylbenzenes to form 1-(4-substituted benzyl)-3-carbamoyl-1,2(1,4)-dihydropyridin-2(4)-iminium bromides. The optimal reaction conditions were found and the resulting iminium salts were characterized by 1H and 13C NMR spectra. No transmission of electronic effect of the substituent at the benzene ring on the spectral properties of dihydropyridine moiety was observed. The possible reason is discussed.

Conformational structure of ethylene glycol dibenzoate. Vibrational and NMR spectra

1981 ◽  
Vol 46 (8) ◽  
pp. 1913-1929 ◽  
Author(s):  
Bohdan Schneider ◽  
Pavel Sedláček ◽  
Jan Štokr ◽  
Danica Doskočilová ◽  
Jan Lövy
Keyword(s):  
Ethylene Glycol ◽  
Vibrational Spectra ◽  
Nmr Spectra ◽  
Coupling Constants ◽  
Conformational Structure ◽  
Infrared And Raman Spectra ◽  
H Nmr ◽  
Liquid States ◽  
Crystalline Forms ◽  
C Nmr

It was found that three crystalline forms of ethylene glycol dibenzoate can be prepared. Infrared and Raman spectra of these three forms, as well as of the glassy and liquid states, were measured. From 3JHH coupling constants obtained by analysis of the 13C satellite band of the -CH2- group in 1H NMR spectra, and from the 3JCH coupling constants of the -CO.O.CH2- fragment obtained by analysis of the carbonyl band in 13C NMR spectra it was found that in the liquid state the -CH2-CH2- group exists predominantly in the gauche conformational structure, and the bonds C-O-C-C assume predominantly a trans orientation. The results of the analysis of NMR and vibrational spectra were used for the structural interpretation of conformationally sensitive bands in vibrational spectra of ethylene glycol dibenzoate.

13C NMR spectra of 1-aryl-ferrocenylethylenes

1986 ◽  
Vol 51 (3) ◽  
pp. 670-676 ◽  
Author(s):  
Eva Solčániová ◽  
Štefan Toma ◽  
Tibor Liptaj
Keyword(s):  
13C Nmr ◽  
Nmr Spectra ◽  
Substituent Effects ◽  
13C Nmr Spectra ◽  
Bridge Group ◽  
C Nmr ◽  
Electron Effects

13C NMR spectra of 18 ferrocene analogues of trans stilbenes (1-aryl-2-ferrocenylethylenes) were measured. It was found that bridge group weakens the transfer of the substituent electron effects into ferrocene nucleus, especially distinctly into 3',4'positions of cyclopentadienyl ring. The transfer of substituent effects into β-position of the bridge -CH=CH- is greater in derivatives studied by us than in stilbenes. Synthesis of 1-(4-dimethylaminophenyl)-2-ferrocenylethylene is described.

The synthesis and stereochemistry of the ternary cobalt(III) complex with a stereospecific ligand derived from (S)-leucine

1986 ◽  
Vol 51 (2) ◽  
pp. 318-326 ◽  
Author(s):  
Milan Strašák ◽  
Pavol Novomeský
Keyword(s):  
Ir Spectroscopy ◽  
Aqueous Medium ◽  
Absorption Spectroscopy ◽  
Absolute Configuration ◽  
Nmr Spectra ◽  
Methyl Groups ◽  
Electron Absorption Spectroscopy ◽  
Electron Absorption ◽  
C Nmr

A new stereospecific ligand, ethylenediamine-N,N'-di(S)-α-isocapronic acid, was synthesized by condensation of (S)-leucine with 1,2-dibromoethane in alkaline aqueous medium. It follows from the 1H and 13C NMR spectra that the terminal methyl groups are chemically and magnetically nonequivalent. Of the four theoretically possible isomers of the ternary cobalt (III) complex with ethylenediamine, separation on catex yielded only one, whose absolute configuration was determined by a combination of 1H and 13C NMR, electron absorption spectroscopy and CD and IR spectroscopy.

17O and 13C NMR spectra of some geminal diacetates

1988 ◽  
Vol 53 (3) ◽  
pp. 588-592 ◽  
Author(s):  
Antonín Lyčka ◽  
Josef Jirman ◽  
Jaroslav Holeček
Keyword(s):  
13C Nmr ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
The Other ◽  
13C Nmr Spectra ◽  
Other Hand ◽  
Carboxylic Esters ◽  
C Nmr ◽  
Oxygen Atoms

The 17O and 13C NMR spectra of eight geminal diacetates RCH(O(CO)CH3)2 derived from simple aldehydes have been measured. In contrast to the dicarboxylates R1R2E(O(CO)R3)2, where E = Si, Ge, or Sn, whose 17O NMR spectra only contain a single signal, and, on the other hand, in accordance with organic carboxylic esters, the 17O NMR spectra of the compound group studied always exhibit two well-resolved signals with the chemical shifts δ(17O) in the regions of 183-219 ppm and 369-381 ppm for the oxygen atoms in the groups C-O and C=O, respectively.

Carbon-13 and nitrogen-14 NMR spectra of 1-(substituted phenyl)pyridinium salts

1980 ◽  
Vol 45 (10) ◽  
pp. 2766-2771 ◽  
Author(s):  
Antonín Lyčka
Keyword(s):  
Heavy Water ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Pyridinium Salts ◽  
Nmr Signals ◽  
C Nmr

The 13C and 14N NMR spectra of 1M solutions of 1-(substituted phenyl)pyridinium salts (4-CH3, 4-OCH3, H, 4-Cl, 4-Br, 4-I, 3-NO2, 4-NO2, 2,4-(NO2)2 (the 13C NMR only)) have been measured in heavy water at 30 °C. The 13C and 14N chemical shifts, the 1J(CH) coupling constants, some 3J(CH) coupling constants, and values of half-widths Δ 1/2 of the 14N NMR signals are given. The 13C chemical shifts of C(4) correlate with the σ0 constants (δC(4) = (1.79 ± 0.097) σ0 + (147.67 ± 0.041)), whereas no correlation of the nitrogen chemical shifts with the σ constants has been found. The half-widths Δ 1/2 correlate with the σ0 constants (Δ 1/2 = (76.2 ± 4.9) σ0 + (106.4 ± 2.2)) except for 1-phenylpyridinium chloride.

Synthesis of the six isomeric thieno[c]-fused 1,5- and 1,6-naphthyridines

1991 ◽  
Vol 56 (11) ◽  
pp. 2340-2351 ◽  
Author(s):  
Salo Gronowitz ◽  
Johan Malm ◽  
Anna-Britta Hörnfeldt
Keyword(s):  
Nmr Spectra ◽  
Coupling Reaction ◽  
One Pot ◽  
C Nmr

trough the use of Pd(0)-catalyzed coupling between 2- and 4-formyl-3-thiopheneboronic acids and 3-amino-2-bromopyridine and 4-acetamido-3-bromopyridine, convenient one-pot procedures for the preparation of thieno[2,3-c]-1,5-naphthyridine, thieno[3,4-c]-1,5-naphthyridine, thieno-[2,3-c]-1,6-naphthyridine, and thieno[3,4-c]-1,6-naphthyridine have been developed. In order to obtain thieno[3,2-c]-1,6-naphthyridine 2-(tributylstannyl)-3-thiophene aldehyde had to be used, since the organometallic partner in the coupling reaction, 3-formyl-2-thipheneboronic acid, is too easily deboronated. The effect of silver(I) oxide and thallium(I) carbonate on the coupling was studied. 1H and 13C NMR spectra of the six isomeric thieno{c]-fused 1,5- and 1,6-naphthyridines are discussed.

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