Purification of crude cottonseed oil and technical gossypol on a chitin sorbent

It has been shown that the use of chitin (technical), which is a production waste, as adsorbent permits the clarification of black cottonseed oil and the purification of technical gossypol.     

Synthesis ofN-methacryloyl- andN-allyl-substituted derivatives of ethyl 5-oxo-2-pyrrolidinecarboxylate

A method for the preparation of previously unknownN-methacryloyl- andN-allyl-derivatives of ethyl 5-oxo-2-pyrrolidinecarboxylate has been developed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 767–769, March, 1996.     

Synthesis of heterocyclic systems with a carbohydrate fragment

Levoglucosenone reacts with α-aminoazoles to yield azolo[1,5-a]pyrimidine systems fused with a carbohydrate fragment. The reaction oocurs much more smoothly than in the case of other α,β-unsaturated ketones. The reactions of levoglucosenone with β-dicarbonyl compounds (dimedone, barbituric acid) in the presence of a base results in the pyran ring closure, which has never been observed earlier in reactions of β-dicarbonyl compounds with α,β-unsaturated ketones under the conditions of basic catalysis. The structures of products were established by IR and NMR spectroscopy. For Part 3, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 553–558, March, 1997.     

Circular dichroism of optically active planar chiral cyclopalladium ferrocene derivatives. Investigation of the dimer-monomer equilibrium

The concentration dependence of the circular dichroism spectra of optically active dinuclear 2-dimethylaminomethylferrocenylpalladium chloride was studied in two solvents. The observed changes in the position and intensity of the Cotton effects were interpreted as a consequence of the dimer-monomer equilibrium. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1411–1413, July, 2007.     

Complexation of chitosan with maleic acid copolymers

The complexation of chitosan with alternating copolymers of maleic acid with N-vinylpyrrolidone, ethylene, or styrene is studied. It is found that the process is of a cooperative character and that the binding constants and the Hill parameters are dependent on the nature of a nonionogenic comonomer maleic acid in the synthetic polyanion and on the conditions of complexation. The data of atomic force microscopy and turbidimetric titration confirm the effect of temperature on the conformation of interacting macromolecules and the size of macromolecular aggregates. It is shown that the composition and yield of insoluble interpolyelectrolyte complexes at constant pH are determined by the reactant ratio, the temperature, and the initial concentration of polyelectrolytes.     

Synthesis and circular dichroism of the optically active dendrimers with the planar chiral ferrocene core

The (S)- and (R)-enantiomers of new planar chiral enantiomerically enriched Frechet-type dendrimers with the 1,2-disubstituted ferrocene core were synthesized from one (S)-enantiomeric precursor. The synthesized compounds were characterized by the circular dichroism spectra.     

Selective racemization of amino acid amides in the presence of amino acids

Conclusions The significant differences in the racemization rates of amino acids and the corresponding amides make it possible to carry out selective racemization of amides in the presence of optically active amino acids.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1593–1596, July, 1986.     

Synthesis of heterocyclic systems with a carbohydrate fragment

The reactions of levoglucosenone with urea, thiourea andN-cyano- andN-nitroguanidines result in pyrimidine systems fused with a carbohydrate fragment. In all cases, the cyclization occurs stereospecifically. The structures of different products of conversion of levoglucosenone were established on the basis of NMR and X-ray diffraction data.