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《Mendeleev Communications》2022,32(4):537-539
The two novel conglomerates were obtained by crystallization of racemic (2'S,3aS,6aR)/(2'R,3aR,6aS) (glycoluril-1-yl)-3-methylbutanoic acid and (2'R,3aR,6aR)/(2'S,3aS,6aS) (4,6-dimethylglycoluril-1-yl)pentanoic acid synthesized by highly diastereoselective condensation of 4,5-dihydroxy- imidazolidin-2-ones with racemic ureido acids. The differences in the molecular geometry of synthesized racemates were studied by X-ray diffraction that showed them to crystallize as conglomerates in non-centrosymmetric space groups Pna21 and P212121, respectively 相似文献
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A. N. Kravchenko A. S. Sigachev E. Yu. Maksareva G. A. Gazieva N. S. Trunova B. V. Lozhkin T. S. Pivina M. M. Il’in K. A. Lyssenko Yu. V. Nelyubina V. A. Davankov O. V. Lebedev N. N. Makhova V. A. Tartakovsky 《Russian Chemical Bulletin》2005,54(3):691-704
Two general procedures were developed for the synthesis of chiral N-mono-, N, N′-di-, N, N′ N″-tri-, and N, N′, N″, N′″-tetraalkylglycolurils based on the reactions of 4,5-dihydroxy-imidazolidin-2-ones or glyoxal with one or two moles of alkylureas, respectively, by acid catalysis. The reactions of N-monoalkyl- and N, N′-dialkylureas with glyoxal proceed regioselectively. The mechanism of these reactions was suggested and partly confirmed by quantum-chemical calculations and experimental data. The enantiomeric separation of some chiral glycolurils by chiral-phase HPLC was carried out for the first time.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 680–692, March, 2005. 相似文献
3.
Synthesis of glycoluril tetramer bearing hydrogen atoms on its convex face and framed by two xylylene units is reported. This tetramer forms dimeric aggregates in the solid state. Host–guest properties of the tetramer with various ammonium and pyridinium guests were determined using 1H NMR spectroscopy. The results were compared with structurally related host molecules. 相似文献
4.
G. A. Gazieva A. N. Kravchenko N. S. Trunova N. N. Makhova 《Russian Chemical Bulletin》2007,56(11):2272-2276
α-Ureidoalkylation of sulfamides with 2-hydroxymethyl-, 2,6-and 2,8-bis(hydroxymethyl)-, and 2,4,6,8-tetrakis(hydroxymethyl)glycolurils
gave novel bi-, tri-, and tetracyclic fused systems combining the glycoluril and sulfamide fragments.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2195–2199, November, 2007. 相似文献
5.
Kravchenko A. N. Maksareva E. Yu. Belyakov P. A. Sigachev A. S. Chegaev K. Yu. Lyssenko K. A. Lebedev O. V. Makhova N. N. 《Russian Chemical Bulletin》2003,52(1):192-197
New (1R*,5S*)-2-R-2,4,6,8-tetraazabicyclo[3.3.0]octane-3,7-diones containing the terminal carboxy or hydroxy group in the substituent R were synthesized by cyclocondensation of 4,5-dihydroxyimidazolidin-2-one with 1-R-ureas. Single-crystal X-ray diffraction analysis showed that 2-carboxyethyl-2,4,6,8-tetraazabicyclo[3.3.0]octane-3,7-dione crystallizes as a racemate. 相似文献
6.
A. N. Kravchenko A. S. Sigachev G. A. Gazieva E. Yu. Maksareva N. S. Trunova K. A. Chegaev K. A. Lyssenko D. V. Lyubetsky M. I. Struchkova M. M. Il’in V. A. Davankov O. V. Lebedev N. N. Makhova V. A. Tartakovsky 《Chemistry of Heterocyclic Compounds》2006,42(3):365-376
The N-hydroxymethylation, N-acetylation, and N-acetoxymethylation of mono-, di-, and trialkylglycolurils by reaction with
the electrophilic reagents formaldehyde and acetaldehyde have been studied. General methods have been developed for the preparation
of mono-, di-, and tri-N-hydroxymethylglycolurils by treatment of differently substituted N-alkylglycolurils with formaldehyde
(as hemiformal in methanol) and the synthesis of di-N-and tri-N-acetyl-or N-acetoxymethylglycolurils via the electrophilic
substitution of hydrogen atoms for an acetyl group at the nitrogen or oxygen atoms in the hydroxymethyl groups of glycolurils
using acetic anhydride. The regioselectivity of the reaction of the 2-t-Bu-and 2-c-C6H11-glycolurils with formaldehyde has been shown to yield a 4,6-di(hydroxymethyl) derivative. It was found that the hydroxymethylation
of 2,4-and 2,6-dialkylglycolurils occurs regioselectively with a stoichiometric ratio of glycoluril to hemiformal and permits
preparation of their mono-and dihydroxymethyl derivatives. The enantiomeric analysis of the obtained compounds has been carried
out for the first time using HPLC on chiral phases. X-ray analysis has been carried out on the previously unreported racemic
2,6-diacetoxymethyl-4,8-dimethylglycoluril.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 411–423, March, 2006. 相似文献
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