PMR spectra of epoxychalcones

The PMR spectra of the epoxides of chalcone and eight of its 4- and 4-substituted derivatives (CH₃, OCH₃, Cl, and NO₂) and of phenyl vinyl ketone in acetone and carbon tetra-chloride were measured. It is shown that these compounds belong to the trans series and exist in hindered conformations. The transmission effects of the epoxide ring and the carbonyl group in epoxychalcone molecules are discussed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1587–1590, December, 1972.     

PMR spectra of N-substituted phenothiazines

The PMR spectra of N-substituted phenothiazines were investigated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1486–1488, November, 1970.     

PMR spectra of difuroyl peroxides

The PMR spectra of difuroyl peroxides were recorded. It is shown that the introduction of a peroxide grouping in place of an anhydride grouping does not lead to changes in the spectrum.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, p. 163, February, 1974.     

PMR spectra of sulfur-containing 1-organylsilatranes

Conclusions The¹H chemical shifts of sulfur-containing 1-organylsilatranes of type YCH₂Si(OCH₂-CH₂)₃N, where Y RS, RS(O), and of sulfonium salts of the silatrane series of type [YCH₂Si-(OCH₂CH₂)₃N]I^–, where Y = RRS⁺, are determined by the valence state of the sulfur atom and the steric stresses. The molecular conformation of the studied compounds was established.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 464–467, February, 1979.     

PMR spectra of natural stilbene compounds

Summary 1. The PMR spectra of 13 natural stilbenes have been studied.2. The dominating role of -electron interaction of the fragments of the stilbene molecule in the screening of the aromatic and olefinic protons has been shown. A series of increments presenting interest for determining the structure of stilbene compounds is proposed.3. It has been established that the nature and nature and number of the substituents in the aglycone part of the molecule have no influence on the screening of the anomeric proton of glycosidated stilbenes, but it does depend on the position of attachment of the carbohydrate fragment.A. A. Zhdanov Irkutsk State University. Irkutsk Institute of Organic Chemistry, Siberian Branch of the Academy of Sciences of the USSR. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 3–10, January–February, 1976.     

PMR spectra of natural stilbene compounds

1. The PMR spectra of 13 natural stilbenes have been studied. 2. The dominating role of π-electron interaction of the fragments of the stilbene molecule in the screening of the aromatic and olefinic protons has been shown. A series of increments presenting interest for determining the structure of stilbene compounds is proposed.     

PMR spectra of dimers of cyclopentadienyl compounds

The PMR spectra of cyclopentadine endo-dimer, its 1y-acetoxy-derivative and the dimer of spiro-heptadiene have been thoroughly studied. The assignment is proved by the use of spindecoupling experiments and the INDOR-technique. The relative signs of several coupling constants were found and used for the assignment. General trends in the proton chemical shifts and coupling constants are discussed for the derivatives of the cyclopentadiene dimer and for the substituted cyclopentadiene dimers.     

PMR spectra of catechins and their derivatives

Summary The PMR spectra of catechins, gallocatechins, epigallocatechin gallate, and their acetyl derivatives have been analyzed and the structures of the compounds investigated have been confirmed.The parameters of the signals of the H-2 and H-3 protons that have been found and also the nature of their change on acetylation enable a compound investigated to be assigned unambiguously to the normal or to the epi series.Division of Bioorganic Chemistry, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 46–50, January–February, 1976.     

Structure and PMR spectra of isoquercitrin and hirsutrin

Chemistry of Natural Compounds - 1. Two isomers of quercetin 3-glucoside are present in the flowers and leaves of the cotton plant of variety 108-F: hirsutrin, quercetin 3-β-D-glucopyranoside;...