Home
→
Browsing by Author

Browsing by Author "Klimovitskii E."

Now showing items 21-40 of 61

Phosphorinane and enol rings in one molecule. Evidence for reciprocal stabilization of half-chair conformations

Polozov A.; Khotinen A.; Klimovitskii E. (1996)

The X-ray crystal structure of 2-(2′,4′-dioxo-3′-pentyl)-5,5-dimethyl-2-oxo-1,3,2- dioxaphosphorinane (2) reveals significant half-chair distortion of the axially oriented cis-enol ring. The molecule also undergoes in-plane ...
Raman spectra and conformations of 2,2-dialkyl-1,3-dithio-5,6-benzocycloheptenes: coexistence of chair, boat and twist-boat forms

Sobolev P.; Shakirov I.; Shagidullin R.; Klimovitskii E.; Strel'nik D. (1992)

Raman spectroscopy has been applied to the title compounds; dithiaketals of acetone, methyl-ethylketone, ethylketone, pinacolone, cyclohexanone and fluorenone. A three-component chair⇋boat⇋twist-boat boat conformational ...
Separation of Cross-Relaxation and Exchange in Two-Site Spin Systems with Weak Spin-Spin Couplings

Klochkov V.; Shaikhutdinov R.; Khairutdinov B.; Klimovitskii E.; Findeisen M.; Berger S. (2003)

A ratio relating the cross-relaxation rates, rate constants, and cross-peak and diagonal peak integrals is used for the analysis of exchanging two-site spin systems with weak scalar spin-spin couplings to extract the rate ...
Seven-membered acetals based on cis-2,3-Dichloro-2-butene-1,4-diol

Arbuzov B.; Klimovitskii E.; Timirbaev M. (1980)

cis-2,3-Dichloro-2-butene-1,4-diol was obtained by reduction of dichloromaleic anhydride with lithium aluminum hydride. Condensation of the diol with carbonyl compounds leads to seven-membered unsaturated acetals, viz., ...
Spatial structure of 2,4,6-trimethyl-1,3,5-dioxathiane and its S,S-dioxide

Arbuzov B.; Klimovitskii E.; Yuldaaheva L.; Guzovskaya L. (1974)

Based on the data of the method of dipole moments and NMR spectroscopy, 2,4,6-trimethyl-1, 3, 5-dioxathiane and its S, S-dioxide have an armchair conformation with an equatorial cis-cis arrangement of the methyl groups. © ...
Spatial structure of meldrum acid and some of its derivatives

Klimovitskii E.; Yuldasheva L.; Arbuzov B. (1973)

On the basis of the dipole moments, Meldrum acid, its monomethyl derivatives, and 2-phenyl-1,3-dioxa-4,6-cyclohexadione in benzene solution have the bathtub conformation, while 2,2,5,5-tetramethyl-1,3-dioxa-4,6-cyclohexadione ...
Stereochemical transformations of some seven-membered pyridoxine dimethyl ketals

Petukhov A.; Strel'nik A.; Fedorenko V.; Litvinov I.; Lodochnikova O.; Shtyrlin Y.; Klimovitskii E. (2007)

According to the data of single crystal X-ray diffraction analysis and computational methods, the seven-membered rings of acylated pyridoxine acetonides have C 2 symmetry. Two stereochemical transformations in solutions, ...
Stereochemistry of 1,3-dithia-5,6-benzocycloheptene-s-oxides

Klimovitskii E.; Kikilo P.; Dobrynin A.; Kataeva O.; Litvinov I.; Fedorenko V.; Shtyrlin Y. (2004)

According to dynamic 13C NMR spectroscopy trans-2-R-(R=Ph, Me, Et, Pri)-5,6-benzocycloheptene-1-oxides at -60°C in CDCl 3 exist as an equilibrium mixture of the chair and boat forms with the substituents in the equatorial ...
Stereochemistry of reaction of 2,3-dichlorotetrahydropyrans with Grignard reagents

Arbuzov B.; Klimovitskii E.; Yuldasheva L.; Remizov A.; Lygin A. (1974)

1. The reaction of the isomeric 2,3-dichlorotetrahydropyrans with Grignard reagents obeys thermodynamic control; the formed 2-R-3-Cl-tetrahydropyrans have the conformation of an armchair with a diequatorial arrangement of ...
Stereochemistry of seven-membered heterocycles - 1. Chair-twist inversion in the 2-arylbenzo[e]-1,3-dioxepanes

Arbuzov B.; Klimovitskii E.; Remizov A.; Sergeeva G. (1979)

Studies based on IR spectroscopy and the measurements of dipole moments show that the 2-(p-X-phenyl)-benzo[e]-1,3-dioxepanes exist as equilibrium mixtures of chair and twist conformers. © 1980 Plenum Publishing Corporation.
Stereochemistry of seven-membered heterocycles 11. Isoenergy chair-twist conformation equilibrium in phthalylformal and its 2-phenyl derivative

Klimovitskii E.; Klochkov V.; Timirbaev M.; Chernov P.; Aganov A.; Arbuzov B. (1983)

By means of dynamic13C NMR, spectra have been obtained for the "frozen" chair and twist conformers of phthalylformal and its 2-phenyl derivative. The γ-effects of the phenyl substituent have been analyzed for both ...
Stereochemistry of seven-membered heterocycles 5. The conformation of 1.3-dioxacyclohept-5-enes

Abuzov B.; Klimovitskii E.; Remizov A.; Timirbaev M. (1981)

1. According, to the results of dipole moment and IR and Raman spectroscopy methods, the butenediol acetal's (I)-(IX) are characterized by a conformational equilibrium of the chair and twist forms determined by the influence ...
Stereochemistry of seven-membered heterocycles Communication 12. Flexible form of tetrachlorophthalylformal and dipole moment of COCOC fragment in γ1 conformation

Arbuzov V.; Klimovitskii E.; Timirbaev M. (1983)

1. According to IR and13C NMR spectroscopic data, tetrachlorophthalylformal exists in the flexible form. 2. By the use of tetrachlorophthalyl sulfite as a model compound, the relative conformational energy of the ...
Stereochemistry of seven-membered heterocycles Communication 16. Dipole moments, IR,1H, and13C NMR spectra, and conformations of 4-methyl-, 4-phenyl-, and isomeric 4,7-dimethyl-2,2-pentamethylene-1,3-di0xa-5,6-benzocycloheptenes

Klimovitskii E.; Sergeeva G.; Enikeev K.; Il'yasov A.; Arbuzov B. (1985)

1. 1H NMR,13C NMR, and IR spectroscopy and dipole moment measurements showed that the conformational mobility of 4-methyl-, 4-phenyl-, and trans-4,7-dimethyl-2,2-pentamethylene-1,3-dioxa-5,6-benzocycloheptenes is a consequence ...
Stereochemistry of seven-membered heterocycles. 2. IR spectra, dipole moments, and inductive effect of the alkyl groups in 2-alkylbenz[e]-1,3-dioxepanes

Arbuzov B.; Klimovitskii E.; Remizov A.; Sergeeva G. (1980)

1. The conformational equilibrium, chair (e)-twist, which is anancomerically shifted toward the chair form for R=C(CH3)3, is characteristic for 2-benz[e]-1,3-dioxepanes, where R=H, CH3, C2H5, n-C3H7, and i-C3H7. 2. A ...
Stereochemistry of seven-membered heterocycles. 3. Conformation of 5,6-dichloro-1,3-dioxacyclopent-5-enes and the planar-fragment effect

Arbuzov B.; Klimovitskii E.; Remizov A.; Klochkov V.; Aganov A.; Timirbaev M. (1980)

1. It is shown by dipole-moment measurements and IR and PMR spectroscopy that 2-R-5,6-dichloro-1, 3-dioxacyclohept-5-enes (R=C6H5, p-ClC6H4, p-NO2C6H4 and the corresponding cyclohexanone ketal exist in the flexible form; ...
Stereochemistry of seven-membered heterocycles. 4. Dipole moments and conformations of seven-membered ketals of α-halocyclohexanones

Arbuzov B.; Klimovitskii E.; Timirbaev M. (1980)

1. The conformational equilibrium in seven-membered 2-chloro(bromo)cyclohexanone ketals derived from 2-butenediol and its 2,3-dichloro and benzo analogs is ananchomerically shifted in favor of the axial form. 2. A graphical ...
Stereochemistry of seven-membered heterocycles. Communication 14. Synthesis and three-dimensional structure of 4-methyl-1,3-dioxa-5,6-benzocycloheptenes

Klimovitskii E.; Sergeeva G.; Strel'nik D.; Arbuzov B. (1984)

1. On the basis of data obtained by the dipole moment method, cis-2-methyl (or phenyl)-4-methyl-1,3-dioxa-5,6-benzocycloheptenes have an equilibrium of chair and twist forms that is close in quantitative respects to the ...
Stereochemistry of seven-membered heterocycles. Communication 17. PMR spectra and conformation of 2-methyl-2-phenyl-1, 3-dioxa-5,6-benzocycloheptene and its isomeric 4-methyl derivatives

Arbuzov B.; Klimovitskii E.; Sergeeva G.; Strel'nik D.; Enikeev K.; Il'yasov A. (1986)

1. 2-Methyl-2-phenyl-1,3-dioxa-5,6-benzocycloheptene and its isomeric 4-methyl-substituted derivatives exist in the twist conformation. 2. In the PMR of these compounds the benzyl protons and 4-methyl groups are coupled ...
Stereochemistry of seven-membered heterocycles. Communication 18. Graphic processing of dipole moments of cis-2-ARYL-4-R-1,3-Dioxa-5,6-benzocycloheptenes and conformational characteristics of the 4-methyl group

Arbuzov B.; Klimovitskii E.; Sergeeva G.; Strel'nik D.; Monakhova N. (1986)

1. By graphic processing of the dipole moments of cis-2-aryl-4-R-1,3-dioxa-5,6-benzo-cycloheptenes replacement of the H atom by Me(Ph) at C-4 was shown not to change the position of chair-twist equilibrium. 2. The chair-chair ...

Now showing items 21-40 of 61

Search DSpace

Advanced Search

Browse

All of Kazan Federal University Digital Repository

Browsing by Author "Klimovitskii E."

Browsing by Author "Klimovitskii E."

Search DSpace

Browse

All of Kazan Federal University Digital Repository

My Account