Structure of ammonium salts of 2-oxy-1,4-butylene-and 2-oxy-1,5-amylenephosphoric acids

The structures of dioxaphosphepane (I) and dioxaphosphecane (II) salts prepared by hydrolysis of the corresponding bicyclophosphates have been compared. In both cases, hydrolysis occurs with breaking of the P–O bond of the fragment at the secondary carbon atom of bicyclophosphate. In phosphocycles I and II, the endocyclic bond angles O–P–O are 104.2 and 104.9°, and the exocyclic ones are 117.7 and 118.6°, respectively. Conformations of the anions in I and II differ substantially: for I it is a twist conformation^C1T_C4, and for II a distorted armchair. The data obtained are compared with those found earlier for similar molecules.Moscow State Pedagogical University. Translated fromZhurnal Strukturnoi Khimii, Vol. 34, No. 4, pp. 154–160, July–August, 1993.Translated by T. Yudanova     

Furanose Bicyclophosphites as Synthons of Modified Nucleoside Diphosphates

Abstract

Previously we synthesized and examined in detail 1,2- alkylideneglucofuanose 3,5,6-bicyclophosphites; mono- and bicyclophosphates with peculiar chemical and physiological activity were obtained on their base [1]. During the study of their structural dependence, we modified the hydrocarbonic moiety, synthesiz-ed 1,2,3- and 3,5,6-bicyclophosphites and cyclophosphates of gulofuanose, and correlated their features with those of glucose analogues. Furthermore, an additional phosphonate moiety (obtained by a stereoselective reaction of an appropriate ketonic sugar with silylphosphites) was introduced into the glucofuranose 3,5,6-bicyclophosphite molecule to the third carbon atom. As a result, the monosaccharide matrix gained two functional groups containing tri- and fourcoordinated phosphorus.     

X-Ray Diffraction Study of Piperidine Octamolybdate

Piperidine octamolybdate [C₅H₅NH₂]₄[Mo₈O₂₆]·4H₂O (I) has been synthesized and characterized by X-ray diffraction analysis. Crystals I are monoclinic, space group P2₁/n, a=12.892(3), b=9.283(2), c=19.184(4) , =92.50(3)°, V=2293.7(9) ³, Z=2,_calc = 2.317 g/cm³.     

Bicyclophosphites of Terminal-Substituted Glycerols

Abstract

For the first time a systematic study was performed for the phosphorylation of 1,2,3-triols with total amides of phosphorous acid. The initial-matrix-structure dependence of phospholane-phospholane bicyclophosphites was found and investigated. The introducing of terminal substituents into a triol molecule was shown to essentially increase their stability.     

Intramolecular hydrogen bonding in the o-(aminomethyl) phenols

Conclusions The strength of intramolecular hydrogen bonding in the o-(aminomethyl)phenols varies by some 5 kcal/mole, depending on the substituent at the nitrogen atom and in the benzene ring. Steric effects from the substituent determine the bonding strength.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 331–334, February, 1977.     

1.3.2.4.5-dioxadithiazin-2.2.4.4-tetraoxides - new reagents for [2+2] - and [2+4]-cycloadditions to olefins

The titled compounds react with olefins under mild conditions to give 1.2-thiazetidin-1.1-dioxides and/or 1.4.5-oxathiazin-4.4-dioxides being formal versatile sources of 1.2- and 1.4-dipoles. Relation of these paths changes widely depending upon structural effects of alkenes and conditions of the reaction.     

Complexes of 2,3-Dihydroxypyridine with Bivalent Metals. Crystal Structure of 2,3-Dihydroxypyridine

Crystal structure of 2,3-dihydroxypyridine (H₂L) is determined. Mn(HL)Cl · H₂O, Co(HL)Cl · 2H₂O, Cu(HL)Cl, Ni(HL)OH · H₂O, and Zn(HL)OH · H₂O complexes are synthesized by reacting Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) chlorides with H₂L in ethanol solutions and identified. In these complexes, 2,3-dihydroxypyridine is involved in coordination as a monoanion. Spectral parameters of neutral and anionic forms of a ligand are determined and the acidity and complex formation constants are calculated. The compositions of complexes are established.     

Synthesis and Structural Study of 3,5-Cyclophosphorus Derivatives of 1,2-O-Alkylidene-6-Desoxy-6-Halogeno-α-D-Glucofuranoses

Abstract

Reactions of 3,5-halogenocyclophosphata of 1,2-O-alkylidene-6-desoxy-6-halogeno-α-D-glucofuranoses with water, alcohols, and amines were studied, which permit the obtaining of corresponding 3,5-cyclophosphates, their salts, and amides: