Study of the Reactivity of 2-Benzylidene[3]ferrocenophane-1,3-dione with Ethyl Acetoacetate and Some Other C-Nucleophiles

1993 ◽  
Vol 58 (9) ◽  
pp. 2128-2138
Author(s):  
Marta Sališová ◽  
Ľubomír Šebo ◽  
Štefan Toma ◽  
Eva Solčániová
Keyword(s):  
Intramolecular Cyclization ◽  
Michael Addition ◽  
Ethyl Acetoacetate ◽  
Nmr Spectra ◽  
H Nmr ◽  
Michael Adducts ◽  
Pyran Derivative ◽  
Dihydropyridine Derivatives ◽  
Sole Product

Michael addition of C-nucleophiles to 2-benzylidine[3]ferrocenophane-1,3-dione has been studied. In some cases, (ethyl acetoacetate, acetylacetone and malononitrile as the C-nucleophiles) the addition was followed by intramolecular cyclization leading to pyran derivatives. Addition of malononitrile gave the pyran derivative as a sole product. The Michael adducts of ethyl acetoacetate and acetylacetone can be converted to [7]ferrocenophane-1,7-dione derivatives by refluxing in benzene with triethylamine as catalyst. they also easily react with ammonia, under SiO2 catalysis, to give Hantzsch dihydropyridine derivatives. The 1H NMR spectra of the products are discussed.

On the Stereoselectivity of the (-)-Dimenthyl Malonate Addition to α,β-Unsaturated Ketones

1996 ◽  
Vol 61 (12) ◽  
pp. 1805-1814 ◽  
Author(s):  
Ľubomír Šebo ◽  
Juraj Alföldi ◽  
Grety Rihs ◽  
Štefan Toma
Keyword(s):  
Michael Addition ◽  
Pure State ◽  
Nmr Spectra ◽  
Reaction Products ◽  
X Ray ◽  
Unsaturated Ketones ◽  
H Nmr ◽  
The Michael Addition

The Michael addition of (-)-dimenthyl malonate to eight α,β-unsaturated ketones has been studied. The ratio of diastereomers was calculated on the basis of the 1H NMR spectra of the crude reaction products. The diastereomer excess varied from 10 to 50%, depending on the structure of the starting enone. The pure diastereomer produced by addition of (-)-dimenthyl malonate to 2-benzylidene-1,4-indandione was isolated by repeated crystallization. X-ray analysis has shown that the isomer is (-)-dimenthyl (R)-2-[1-(1,3-dioxoindan-2-yl)-1-phenylmethyl]malonate (5a). The predominating diastereomers of (-)-dimenthyl(3-ferrocenyl-3-oxophenylpropyl)malonate (1a) and (-)-dimenthyl-2-(1-(1,3-dioxo[3]ferrocenophan-2-yl)-1-phenyl malonate (6a) were also isolated in pure state by careful crystallization.

Synthesis of Some 1,2,4-Triazolo[4,3-c]quinazolines Based on 4-Quinazolylthiosemicarbazides

1994 ◽  
Vol 59 (1) ◽  
pp. 222-226 ◽  
Author(s):  
Katarína Špirková ◽  
Štefan Stankovský ◽  
Miloslava Dandárová
Keyword(s):  
Intramolecular Cyclization ◽  
Nmr Spectra ◽  
Cyclization Reactions ◽  
H Nmr ◽  
Substituted 1

The paper describes the cyclization reactions of substituted 1-(4'-quinazolyl)-4-phenylthiosemicarbazides (Ia - Ie). The thermal intramolecular cyclization gives 2H-1,2,4-triazolo[4,3-c]quinazoline-3-thiones (IIa - IId). Heating of I with HgO gives 3-anilino-1,2,4-triazolo[4,3-c]quinazolines (IIIa - IIIe). The IR and 1H NMR spectra of the compounds synthesized are presented.

Synthesis of 3β,4β-cyclopropano-19-nor-A-homosteroids

1985 ◽  
Vol 50 (7) ◽  
pp. 1611-1617 ◽  
Author(s):  
Jiří Joska ◽  
Jan Fajkoš ◽  
Jaroslav Zajíček
Keyword(s):  
Double Bond ◽  
Metal Hydride ◽  
Nmr Spectra ◽  
H Nmr ◽  
Hydride Reduction ◽  
Sole Product

Acetolysis of the tosylate XIII, afforded the olefin XIV as the sole product. Epoxidation of the double bond gave the epoxide XV which on metal hydride reduction yielded the alcohol XVI. The structures of these products were established by spectral and chemical means and conformation of the A-homo ring in the epoxide XV is discussed on the basis of the 1H NMR spectra.

Michael addition of 1,3-cyclopentanedione, 1,3-cyclohexanedione and 1,3-cycloheptanedione to 1-(X-phenyl)-2-nitroethylenes

1984 ◽  
Vol 49 (6) ◽  
pp. 1421-1431 ◽  
Author(s):  
Pavel Hrnčiar ◽  
Igor Čulák
Keyword(s):  
Michael Addition ◽  
Nmr Spectra ◽  
H Nmr ◽  
C Nmr

Michael addition of 1,3-cyclopentanedione, 1,3-cyclohexanedione and 1,3-cycloheptanedione to 1-(X-phenyl)-2-nitroethylenes was studied. 1,3-Cyclopentanedione afforded 2-(1-(X-phenyl)-2-nitroethyl)-1,3-cyclopentanediones (I), 1,3-cyclohexanedione gave 9-(X-phenyl)-8-hydroxyimino-7-oxabicyclo[4,3,0]-1-nonen-2-ones (IIa-IIe),whereas reaction with 1,3-cycloheptanedione led to 10-(X-phenyl)-8-oxabicyclo[5,3,0]-1-decen-2-ones (IIg-IIj) as well as 9,9'-hydroxyaminobis(10-(X-phenyl)-8-oxabicyclo[5,3,0]-1-decen-2-ones) (III). Products I were isolated also in the addition of 1,3-cyclohexadione and 1,3-cycloheptanedione to 1-(X-phenyl)-2-nitroethylene when X=H or an electron accepting substituent and the reaction was performed at -5 to 0°C, and were converted into II. The structure of the compounds and mechanism of the conversion of I to II is discussed on the basis of IR, 1H NMR and 13C NMR spectra.

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.

Preparation and absolute configuration at C(20) of 21-nor-5α-chol-22-en-24→20-olide derivatives

1981 ◽  
Vol 46 (4) ◽  
pp. 917-925 ◽  
Author(s):  
Vladimír Pouzar ◽  
Miroslav Havel
Keyword(s):  
Absolute Configuration ◽  
Nmr Spectra ◽  
Lithium Salt ◽  
H Nmr ◽  
Chemical Correlation ◽  
Unsaturated Lactones

Reaction of the aldehyde I with the lithium salt of 1-(2-tetrahydropyranyloxy)-2-propyne yielded the compounds II and IV. From the compound II the lactone XII was prepared via the intermediates III and X, the lactone XVIII was prepared from the substance IV via the intermediates V and XVI. The unsaturated lactones XII and XVIII were also prepared by sulfenylation and dehydrosulfenylation of the saturated lactones XIII and XIX. Based on chemical correlation and 1H-NMR spectra analyses of the compounds II and IV, the lactone XII was assigned the 20R-configuration whereas the lactone XVIII was allotted the 20S-configuration.

New type of addition to 5-substituted 4-arylidene-2-(4,5-dihydrofurfurylidene)-N,N-dimethyliminium bisperchlorates. Preparation of 4-substituted 5-(N,N-dimethylamino)-2-furancarbaldehydes

1986 ◽  
Vol 51 (3) ◽  
pp. 573-580 ◽  
Author(s):  
Tibor Gracza ◽  
Zdeněk Arnold ◽  
Jaroslav Kováč
Keyword(s):  
Nmr Spectra ◽  
Addition Reaction ◽  
H Nmr ◽  
Organic Bases ◽  
New Type

4-Arilidene-5-(N,N-dimethyliminium)-2-(4,5-dihydrofurfurylidene)-N,N-dimethyliminium bisperchlorate I undergoes a 1,4-addition reaction with organic bases under re-formation of the furan nucleus; this behaviour has been utilized in the preparation of new 4-substituted 5-(N,N-dimethylamino)-2-furancarbaldehydes II, III. The structure of the prepared compounds has been confirmed by 13C and 1H NMR spectra.

Preparation, properties and structure of some intermediate nido- and arachno-monocarbaboranes

1981 ◽  
Vol 46 (10) ◽  
pp. 2345-2353 ◽  
Author(s):  
Karel Baše ◽  
Bohumil Štíbr ◽  
Jiří Dolanský ◽  
Josef Duben
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Nmr Spectra ◽  
Liquid Ammonia ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Starting Compound

The 6-N(CH3)3-6-CB9H11 carbaborane reacts with sodium in liquid ammonia with the formation of 6-CB9H12- which was used as a starting compound for preparing the 4-CB8H14, 9-L-6-CB9H13 (L = (CH3)2S, CH3CN and P(C6H5)3), 1-(η5-C5H5)-1,2-FeCB9H10-, and 2,3-(η5-C5H5)2-2,31-Co2CB9H10- carboranes. The 4-CB8H14 compound was dehydrogenated at 623 K to give 4-(7)-CB8H12 carborane. Base degradation of 6-N(CH3)3-6-CB9H11 in methanol resulted in the formation of 3,4-μ-N(CH3)3CH-B5H10. The structure of all compounds was proposed on the basis of their 11B and 1H NMR spectra and X-ray diffraction was used in the case of the transition metal complexes.

The preparation of 3-amino-3-deoxy-1,2-O-isopropylidene-α-L-erythrofuranose, 3-amino-3-deoxy-1,2-O-isopropylidene-β-D-threofuranose and their derivatives

1980 ◽  
Vol 45 (12) ◽  
pp. 3378-3390 ◽  
Author(s):  
Jiří Jarý ◽  
Milena Masojídková ◽  
Ivan Kozák ◽  
Miroslav Marek ◽  
Jan Staněk
Keyword(s):  
Nucleophilic Substitution ◽  
Sodium Azide ◽  
Sodium Benzoate ◽  
Nmr Spectra ◽  
Subsequent Reduction ◽  
H Nmr ◽  
Amino Derivatives

The title amino derivatives VI and XIV were prepared by nucleophilic substitution of p-toluenesulfonyl derivatives II and XVII with sodium azide or hydrazine and subsequent reduction. Nucleophilic substitution of compounds II and XVII with sodium benzoate was also investigated. The 1H NMR spectra of the substances prepared are discussed.

Preparation of (20E)-21-Ethoxycarbonyl-14β,17α-pregna-5,20-dien-3β-yl Hydrogen Butanedioate

1995 ◽  
Vol 60 (4) ◽  
pp. 715-718 ◽  
Author(s):  
Vladimír Pouzar ◽  
Ivan Černý
Keyword(s):  
Title Compound ◽  
Nmr Spectra ◽  
Total Yield ◽  
Reaction Sequence ◽  
Pregnane Series ◽  
H Nmr

The title compound X was prepared according to the recently published procedure for preparation of analogous derivatives in the 5β-pregnane series, using the reaction sequence I -> II -> III -> IV -> V -> VI -> VII -> VII -> IX -> X (total yield 18%). The configuration at ring D centers (14β,17α) follows from the structure of the starting ketone I and was also checked by comparing diol IV with the sample prepared by an independent route. The epimeric purity at C-17 was carefully monitored during the whole synthesis by 1H NMR spectra (singlet of 18-H3).

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