A. M. Korolev

Nitration equilibrium in the glycerol-aqueous-nitric-acid system 3. PMR parameters, conformational structure, and main properties of glycerol and its nitrates

Studies of PMR spectra at a frequency of 294 MHz for glycerol, and its mono-, di-, and trinitrates have been carried out in aqueous solutions of nitric and sulfuric acids and in deuteroacetonitrile. The conformational composition weakly depends on the medium, temperature, and the number of nitrate groups in the molecule. Conformers with CH2 and OH (or ONO2) located in a trans position have a certain preference. The basicity parameters pKBH+ and Φe and semiprotonation points of glycerol (separately for primary and secondary hydroxyl) and glycerol dinitrates have been determined. In these properties glycerol and its dinitrates are similar to monatomic alcohols. Acidity functions of solutions of sulfuric and nitric acids were calculated using glycerol and glycerol dinitrates as indicators. Unlike Hammett bases, alcohols in H2O-H2SO4 and H2O-HNO3 systems of identical molar composition are protonated practically identically.

Study of nitration equilibrium in the glycerin-aqueous nitric acid system. 1. Dependence of the equilibrium constants of nitration reactions on the temperature, acidity of the medium, and structure of the nitrated compound

The equilibrium constants of seven sequential-parallel reactions of conversion of glycerin into glycerin trinitrate in aqueous HNO3 were measured. The effect of the acidity of the medium on the equilibrium nitration constants is correlated with processes of protonation of glycerin and its nitrates. The equilibrium nitration constants are higher for primary hydroxides than for secondary hydroxides, and they decrease in both series in going from glycerin to its dinitrates.

Synthesis and physicochemical properties of cis- and trans-oxolane-3,4-diol derivatives

ConclusionsPhysicochemical properties of oxolane-3,4-diols, their dinitrates, diacetates, and ditosylates have been determined; the standard enthalpies of combustion and formation have also been measured for the first two series of derivatives.

Synthesis and structure oe cis-3,4-oxolanediol dinitrate

Conclusions1.Cis-3,4-oxolanediol dinitrate was obtained by the O-nitration of the corresponding glycol using the HNO3-H2SO4-H2O system.2.The cis-3,4-oxolanediol dinitrate molecule is asymmetric and the crystal structure consists of two enantiomers, i.e., is a racemate.

Nitration equilibrium in the meso-erythritol-aqueous nitric acid system

Twelve equilibrium constants have been measured from 16 for sequential-parallel reactions in meso-erythritol nitration to the fully nitrated compound in aqueous HNO3. Free-energy changes during nitration of the aliphatic polyatomic alcohols, glycerol and meso-erythritol, are highest when diprimary dinitrates (NOON) and (NON) are produced.

Nitration equilibrium of water-soluble carboxycellulose

Maximum and minimum values of the equilibrium constants for nitration of hydroxyl groups in water-soluble carboxycellulose (WSCC) have been estimated. Electronegative substituants and elements of the cellulose structure in the WSCC molecule substantially lower the equilibrium constants for nitration compared with those for polyatomic aliphatic alcohols.

Study of nitration equilibrium in the glycerin-aqueous nitric acid system. 2. Changes in δH and δS in the nitration reaction

The real enthalpies of seven sequential-parallel reactions of nitration of glycerin into glycerin trinitrate were found by combination of the heats of the reactions obtained by the thermochemical method and with the equation for the isobar of the chemical reaction, and the standard enthalpies of formation of glycerin nitrates were calculated with them. The difference in the enthalpies of nitration with respect to different positions in glycerin and its nitrates basically determines the difference in the corresponding equilibrium constants of the nitration reactions.

Rearrangements of oxide rings and chemical transformations in synthesis of partial nitrates of α-epoxy polyhydric alcohols

1. On the basis of the NMR spectra it was established that the reaction of the 2, 3-dinitrates of meso- and d,l-erythritol with an equimolar amount of alcoholic alkali gives a mixture of the isomeric partial nitrates of the epoxy alcohols. 2. The formation of the partial nitrates of the epoxy alcohols was ascertained on the basis of the nitration products of the indicated mixtures, and a scheme was proposed to explain the formation of the obtained compounds. 3. The oxirane-tetrahydrofuran rearrangement was detected in the series of the partial nitrates of α-epoxy polyhydric alcohols.

Migration of α-oxide ring in erythro-3,4-butanediol 1,2-oxide 4-nitrate

Based on a study of the NMR spectra of the products, obtained in the different steps of the synthesis of erythro-3,4-butanediol 1,2-oxide dinitrate, it was found that intramolecular rearrangement, the migration of the α-oxide ring in erythro-3,4-butanediol 1,2-oxide 4-nitrate, exists.

Separation of signals and analysis of NMR spectra of type ABKPQY of a mixture of the erythro and threo isomers of 3,4-butanediol 1,2-oxide dinitrate on a spectrometer with an operating frequency of 200 MHz

1. The existence of the dinitrate of 3,4-butanediol 1,2-oxide as a mixture of the erythro and threo isomers was confirmed on an NMR spectrometer that operated at a frequency of 200 MHz. The spectra of the individual isomers were isolated and analyzed. 2. We synthesized the erythro and threo isomers of 3,4-butanediol 1,2-oxide dinitrate. A study was made of the NMR spectra of these compounds and the relation between the parameters of the spectra and the structure of the diastereomers was discussed. 3. Some members of the partial nitrates of α-epoxy alcohols, namely the 4-nitrates of erythro- and threo-3,4-butanediol 1,2-oxide, were obtained for the first time.