A. D. Shebaldova

Stereochemical peculiarities of the catalytic reduction of sym-octahydrothioxanthylium salts

The three-dimensional structures of the products of catalytic hydrogenation of sym-octahydrothioxanthylium salts in the presence of palladium on carbon were studied by 13C NMR spectroscopy. It was shown that the reaction proceeds stereoselectively with the formation of cis-syn-cis isomers. The stereochemistry of the reduction products is in agreement with the previously proposed reaction mechanism.

Condensation reactions involving the ?-methylene group in series of 5-alkylpyrrolidine-2-thiones and 5-alkyl-1-acetyl-2-pyrrolidones

It is shown that 1-substituted and N-unsubstituted 5-R-pyrrolidine-2-thiones, in contrast to their oxygen analogs, undergo methylenethioalkylation and the Mannich and Michael reactions at the 3 position of the ring; this is due to their higher CH acidity. The results of quantum-chemical calculations (by the MO LCAO method within the CNDO/2 approximation) confirm the similar reactivities of pyrrolidine-2-thiones and 1-acetyl-substituted 2-pyrrolidones.

Investigation of 2,6-diarylthiacyclohexanes and their complexes with Pt(II) and Pd(II) by 1H and 13C NMR spectroscopy

A conclusion regarding a diequatorial orientation of the aryl substituents was drawn on the basis of a study of the 1H and 13C NMR spectra of 2,6-diarylthiacyclohexanes. A trans structure of the complexes with an equatorial S→metal bond was established by a comparative analysis of the 13C NMR spectra of 2,6-diarylthiacyclohexanes and their complexes with Pt(II) and Pd(II).

Reaction of 2-thiopyrrolidones with monochloroacetic acid and its methyl ester

Calculations of the electronic structure of 5-alkyl-2-thiopyrrolidones and their oxygen analogs were carried out by the MO LCAO method in the CNDO/2 approximation. The obtained data were used to discuss the reactivity of the investigated compounds in the alkylation of monochloroacetic acid, leading, in the case of 2-thiopyrrolidones, to the formation of the corresponding thiazolinones.

The oxidation reactions of thiopyrans

A method was developed for the preparation of compounds with 4H-thiopyrone structure by the oxidation of the corresponding 4H-thiopyranes and their condensed analogs by potassium permanganate.