The structure of vincarodine

The structure of vincarodine has been determined to be 1 by an investigation of its IR.-, UV.-, ¹H- and ¹³C-NMR.- and mass spectra. A ¹³C-NMR. analysis has been performed on the bases vincamine ( 2 ), epivincine ( 9 ), 14, 15-dehydrovincine ( 7 ) and its 16-epimer ( 8 ).     

Strukturaufklärung von N6-, 9- und 7-Acyladeninen durch 1H-und 13C-NMR-Spektroskopie von Festkörpern und in Lösung

Structure Determination of N⁶-, 9-and 7-Acyladenines by ¹H- and ¹³C-NMR Spectroscopy of Solids and in Solution . Adenine (1) reacts with carboxylic acid anhydrides or chlorides 2 to yield the acyladenine isomers 3–5 . The isomeric structures were determined by ³³C- and ¹H-NMR spectroscopy in solution and by solid-state ¹³C-NMR spectroscopy.     

1H- und 13C-NMR.-Spektren von 6-(p-X-Phenyl)fulvenen. Kurzmitteilung

¹H- and ¹³C-NMR.-spectra of 6-(p-X-phenyl)fulvenes The ¹H- and ¹³C-NMR.-spectra of a series of 6-(p-X-phenyl)fulvenes 3 , measured at 9.39 T (93.9 kgauss), have been analyzed. In these compounds, electronic effects due to the substituent X clearly exert changes in chemical shifts as well as in coupling constants in the 5-membered ring. Small changes in bond length are observed by comparison of the vicinal ¹H, ¹H-coupling constants, whereas changes in charge densities linearly influence the chemical shifts of C(5), C(2) and C(3).     

Poly(alkylene oxide) ionomers VIII. Synthesis of methyl ω-alkenoates and methyl ω-epoxyalkanoates

ω-Alkenoic acids, either commercially available or synthesized, were esterified to their corresponding methyl esters. They were characterized by their infrared, ¹H-, and ¹³C-NMR spectra. The ω-alkenoates prepared were: propenoate (acrylic acid), butenoate, pentenoate, hexenoate, heptenoate, octenoate, nonenoate, and decenoate. These compounds were epoxidized with m-chloroperoxybenzoic acid to the corresponding methyl ω-epoxyalkanoates. The rate of epoxidation of the double bond is found to increase as the double bond is separated from the carbomethoxy group by increasing numbers of methylene groups. When at least three methylene groups are inserted, the rate of epoxidation becomes constant and is similar to the epoxidation of ω-olefins. The methyl ω-epoxyalkanoates were characterized by their infrared, ¹H-, and ¹³C-NMR spectra. Methyl ω-alkenoates and methyl ω-epoxyalkanoates were prepared and characterized, and their purification was studied in preparation for their investigation as monomers for olefin or epoxide polymerization using corrdination initiators.     

1H- und 13C-NMR.-spektroskopische Untersuchungen an den vier diastereomeren (±)-Dihydropalustraminsäure-methylestern; Strukturkorrelation mit (−)-Dihydropalustraminsäure-methylester sowie mit dem Alkaloid Palustrin. 14. Mitteilung über Schachtelhalmalkaloide

¹H-and¹³C-NMR. spectra of methyl esters of the diastereomeric (±)-dihydropalustramic acids; structural correlation of (?)-dihydropalustramic acid with the alkaloid palustrin Unambiguous assignment of cis-trans configuration at the piperidine ring of the four diastereomeric methyl esters of the (±)-dihydropalustramic acids is based on the interpretation of ¹H- and ¹³C-NMR. data. (?)-Dihydropalustramic acid, the important degradation product of the alkaloid palustrin is shown to be threo-cis-[6-(1-hydroxypropyl)-2-piperidyl]acetic acid. The same conclusion holds for palustrin and dihydropalustrin. Therefore, palustrin is threo-cis-17-(1-hydroxy-propyl)-1,5,10-triazabicyclo[11.4.0]heptadec-15-en-11-one.     

Spektroskopische Untersuchungen an Schwefelverbindungen. VII. 1H- und 13C-NMR-spektroskopische Untersuchungen an Alkansulfinsäurechloriden und Chloroschwefligsäurealkylestern

Spectroscopic Studies on Sulphur Compounds. VII. ¹H- and ¹³C-NMR Spectroscopic Investigations of Sulphinic Acid Chlorides and Chloro-sulphurous Acid Alkylesters The temperature dependent ¹H- and ¹³C-n.m.r. spectra of the sulphinic acid chlorides R—S(O)Cl and of the chloro-sulphurous acid alkylesters RO—S(O)Cl with R = CH₃CH₂- and (CH₃)₂CH- have been measured. The differing behaviour of both nuclei is discussed in terms of inversion at the chiral sulphur atom.     

New Acid-Polyfunctional Water-Soluble Phosphazenes: Synthesis and Spectroscopic Characterization

Poly [bis(phenoxy)] phosphazene sulfonic acid and its mixed substitution derivatives containing N-methylsulfonamide, sulfonylaminoacetic, and free sulfonic acid functions have been obtained and characterized by IR and ¹H-, ³¹P-, ¹³C-NMR spectroscopy. The polymers are all water soluble. Poly [bis(4-benzoylphenoxy)] phosphazene sulfonic acid could not be obtained due to chain degradation during the synthesis.     

Hyperfine shifts of the 13C-NMR. in low spin iron(3) porphyrin complexes

The ¹³C-NMR. in Zn(II)(Porphin), Fe(III)(Porphin)(CN₂), Zn(II)(Tetraphenyl-porphin), and Fe(III)(Tetraphenylporphin)(CN₂) have been identified, and the ¹³C hyperfine shifts in the iron complexes evaluated. It was found that dipole-dipole coupling with the electron spin localized in the π-orbitals of the aromatic carbon atoms makes an important contribution, to the ¹³C hyperfine shifts. In a preliminary analysis the experimental spin density distribution obtained from the combined ¹H- and ¹³C-NMR.-data is compared with theoretical models of the iron porphyrin complexes.     

Propellanes. Part LXXX. Baeyer-Villiger Oxidation of [4.3.3]Propellane-8,11-dione

Oxidation of the title compound with m-chloroperbenzoic acid affords a keto-lactone, two bis-lactones and a bis-spirolactone, in varying amounts depending upon the reaction conditions. The structures were established by means of X-ray diffraction, ¹H- and ¹³C-NMR spectroscopy.     

Chemistry of Benzocyclopropenes. 1H-and 13C-NMR. Spectra of 2, 5-dideuterio-1-fluorobenzocyclopropenium ion

Preparation of 1, 1-difluorobenzocyclopropene (4) and of its 2, 5- and 3, 4-dideuterio derivatives 4a and 4b is reported. Upon ionization in cold fluorosulfonic acid, 4 affords 1-fluorobenzocyclopropenium ion (6) . ¹H- and ¹³C-NMR. spectra of 4 and 6 are assigned on the basis of the data for the specifically deuteriumlabelled compounds 4a and 6a . Hydrolysis of 6a leads to 2, 5-dideuteriobenzoic acid (7a) .     

Conformational Analysis of the cis- and trans-Isomers of FK506 by NMR and Molecular Dynamics

The potent immunosuppressant drug FK506 ( 2 ) has been examined by ¹H- and ¹³C-NMR spectroscopy and NOE-restrained molecular dynamics to elucidate the conformation in solution. A combination of two- and three-dimensional NMR techniques was used to completely assign the ¹H- and ¹³C-NMR chemical shifts of the two configurational isomers resulting from the cis-trans isomerization about the single amide bond. Hetero- and homonuclear coupling constants were measured to assign the diastereotopic methylene protons at C(16), C(18), and C(23). Intramolecular H? H distances were defined from NOESY spectra recorded at ?30° in CDCl₃ and used as constraints in molecular-dynamics simulations. The conformational preferences of 2 in solution are discussed in light of the constitutional features recently proposed to be necessary for binding and activity.     

Zum Problem Camphenilansäure—Camphenansäure und Isocamphenilansäure—Isocamphenansäure

The configuration of camphenilanic acid (1) has been determined by NMR-spectroscopic studies.¹H-,¹³C-NMR and 2D-shift correlation spectroscopy have been used. The socalled camphenanic acid is identical with1, isocamphenanic acid appears to be a mixture of1 and2, the same is true for different camphenilanic acids described in the literature.     

Heteronuklear überbrückte tricyclische Systeme. Oxa-brexane- und -brendane

Unsaturated cyclic and bicyclic hydrocarbons react with chloral in presence of aluminium chloride to yield tricyclic oxabrexanes which undergo acid catalyzed rearrangements to oxabrendanes. 1,5-cyclooctadiene gives the new oxa-cyclo[c, d]octahydropentalen. Structural evaluations and stereochemical assignments are discussed on the basis of detailed ¹H- and ¹³C-NMR.-spectra.     

Amidation of syndiotactic poly(2-methylallyl hydrogen carboxylate)

The amidation of syndiotactic polyacids and the ¹H- and ¹³C-NMR spectroscopic characterization of the resulting polyamides are described. The polyacids have been derived from syndiotactic poly(2-methylallyl alcohol) by esterification with cyclic dicarboxylic acid anhydrides, including N^α-protected aspartic acid anhydrides and glutamic acid anhydrides. The poly(hydrogen carboxylate) were in turn condensed with a series of amines, some of which possessed additional functional groups, e.g. (L)-1-phenylethylamine, histamine, and glycine methylester.     

Determination of Compositional,Configurational Sequences in High Conversion Methyl Methacrylate-Methacrylic Acid Emulsion Copolymers Using a Rapid and Selective Counting Procedure

High conversion methyl methacrylate (MMA)-methacrylic acid (MA) copolymers prepared by two different emulsion polymerization processes were characterized in terms of composition and sequence distribution by ¹H- and ¹³C-NMR, taking into account the conversion effect. A rapid and selective counting procedure for calculating the compositional configurational pentads (512 values) in these copolymers is described. From this counting procedure and using the Klesper's assignment of the 18 peaks observed in the ¹³C-NMR carbonyl resonance spectrum of the copolymers, a relatively good agreement was found between the calculated and experimental fractions of each peak intensity. Moreover, this study allows differences in compositional homogeneity to be characterized as a function of the nature of the emulsion polymerization process.     

Arylierungen von cyclischen Guanidin-Analogen mit α-halogenierten Anthrachinonen: neue Anthrapyrimidine

Arylation Reaction of Cyclic Guanidine-Analogs with α-Halo- anthraquinones: New Anthrapyrimidines 2-Amino-benzimidazole gives on Ullmann-reaction with α-halo-athraquinones such as 1-amino-4-bromoanthraquinone-2-sulfonic acid (la) the new benzimidazo-anthrapyrimidine 2a , whereas 3-amino- triazole gives under the same conditions two products: the 1,2,4-triazoloanthrapyrimidine 7 and l-amino-4-(3-amino-1,2,4- triazolyl)anthraquinone-2-sulfonic acid ( 8 ). The new structures were elucidated by ¹H- and ¹³C-NMR. and X-ray analysis.     

Composition of Ni2+ cation solvation shell in NiCl2–methanol solution by multinuclear NMR

¹H-, ²H- and ¹³C-NMR spectra have been used to test the Ni²⁺ solvation shell composition in the 1.1 molal methanol solution of NiCl₂. It has been confirmed that Cl^? anion takes part in the nearest environment of Ni²⁺ cation at all the temperatures investigated. Using ²H-NMR allowed us to detect for the first time OD-signal of methanol in the primary solvation shell of Ni²⁺ cation. Both ²H- and ¹³C-NMR spectra show that the composition of the cation solvation shell becomes more complicated at temperatures lower than 220?K.     

Studies on mononuclear chelates derived from substituted Schiff-base ligands (part 6): synthesis and characterization of a new 3-ethoxysalicyliden- p -aminoacetophenoneoxime and its complexes with cobalt(II), nickel(II), copper(II) and zinc(II)

Schiff-base complexes of cobalt(II), nickel(II), copper(II) and, zinc(II) with 3-ethoxysalicyliden-p-aminoacetophenoneoxime (HL) were prepared and characterized on the basis of elemental analyses, IR, ¹H- and ¹³C-NMR, electronic spectra, magnetic susceptibility measurements, molar conductivity and thermogravimetric analyses (TGA). A tetrahedral geometry has been assigned to the complexes.     

1H-NMR.-, 13C-NMR.-, UV.- und CD.-Daten von synthetischem (3S, 3′S)-Astaxanthin,seinem 15-cis-Isomeren und einigen analogen Verbindungen

¹H-NMR., ¹³C-NMR., UV. and CD. spectral data of synthetic (3S, 3′S)-astaxanthin, its 15-cis isomer, and some related compounds ¹H-NMR., ¹³C-NMR., UV. and CD. spectra are reported for synthetic (3S, 3′S)-astaxanthin ( 1 ), its 15-cis isomer ( 2 ), its diacetate ( 3 ), and the 15, 15′-didehydro compound ( 5 ). These data prove the identity of the synthetic and the naturally occuring compound 1 . A full interpretation of the ¹H- and ¹³C-NMR. spectra is given and confirms the configuration of all the double bonds. The conformation of the cyclohexene end group of all the compounds is shown to be identical. The signs of the different CD. maxima of 15-cis-astaxanthin are found to be opposite to those of the all-trans compound.     

On the structure of guanylhydrazones derived from aromatic aldehydes

Summary The synthesis of some novel guanylhydrazones derived from aromatic aldehydes (benzylideneaminoguanidines) is described. Structural assignments of these compounds as well as of some already known congeners, particularly with respect to the configuration of the HC=N double bond, were achieved using¹H- and¹³C-NMR data as well as homonuclear NOE difference spectroscopy.

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Zur Struktur von Guanylhydrazonen aromatischer Aldehyde

Zusammenfassung Die Synthese einiger neuer Guanylhydrazone abgeleitet von aromatischen Aldehyden (Benzylidenaminoguanidine) wird beschrieben. Die Strukturzuordnung bei diesen Verbindungen sowie bei einigen literaturbeschriebenen Analoga — besonders im Hinblick auf die Konfiguration an der HC=N Doppelbindung — erfolgte mittels¹H- und¹³C-NMR Spektroskopie sowie mit Hilfe homonuklearer NOE-Differenzspektroskopie.