Preparation of 6-amino-6-deoxy-D-altronic acid and their derivatives

1986 ◽  
Vol 51 (2) ◽  
pp. 391-400 ◽  
Author(s):  
Karel Kefurt ◽  
Karel Čapek ◽  
Zdeňka Kefurtová ◽  
Jiří Jarý
Keyword(s):  
Amino Acid ◽  
Alkaline Hydrolysis ◽  
Nmr Spectra ◽  
Structural Changes ◽  
Catalytic Reduction ◽  
Isopropylidene Derivative ◽  
H Nmr

Methyl 6-azido-3,5-di-O-benzoyl-6-deoxy-α- and -β-D-glucofuranosides (IIIandIV), obtained by methanolysis of 1,2-O-isopropylidene derivative II were converted via 2-O-methanesulfonyl esters V and VI to methyl 2,3-anhydro-6-azido-6-deoxy-α- and -β-D-mannofuranosides (VII or VIII, respectively). Epoxide VII when submitted to alkaline hydrolysis gave methyl 6-azido-6-deoxy-α-D-altrofuranoside (IX) exclusively, while epoxide VIII afforded a mixture of methyl 6-azido-6-deoxy-β-D-furanosides of altro (X) and gluco(XI) configuration in a 5 : 4 ratio. Altrofuranosides IX and X were converted to 6-azido-6-deoxy-D-altrose (XII) the oxidation of which with bromine and catalytic reduction with hydrogen afforded amorphous amino acid XIV, characterized as its tetraacetyllactam XVI. The structural changes of the compounds from individual steps of the synthesis were checked by IR and 1H NMR spectra which are discussed.

Influence of Dodecyltrimethylammonium Halides on Interaction of Phenyltin Compounds with Model Membranes

2001 ◽  
Vol 56 (7-8) ◽  
pp. 623-628
Author(s):  
Bożenna Różycka-Roszak ◽  
Hanna Pruchnik
Keyword(s):  
Phase Formation ◽  
Nmr Spectra ◽  
Structural Changes ◽  
Hexagonal Phase ◽  
Model Membranes ◽  
Phase Behaviour ◽  
Dodecyltrimethylammonium Bromide ◽  
H Nmr ◽  
Dodecyltrimethylammonium Chloride ◽  
Triphenyltin Chloride

The effects were studied of dodecyltrimethylammonium chloride (DTAC), dodecyltrimethylammonium bromide (DTAB) and dodecyltrimethylammonium iodide (DTAI) on thermo­tropic phase behaviour of phosphatidylcholine bilayers, as well as on 1H NMR and 31P NMR spectra, in the presence of diphenyltin dichloride (DPhT) and triphenyltin chloride (TPhT). The obtained results indicate that in the presence of the surfactant studied the interaction of phenyltin compounds with model membranes was changed and the changes depended on the kind of the counterion. The surfactants studied (especially DTAC) decrease the ability of phenyltin compounds to induce structural changes in the bilayer. It is suggested that DTAB, and especially DTAC, prevent DPhT induced interdigitated phase formation as well as formation of an inverted hexagonal phase (HII) in the case of TPhT/DPPC liposomes

N-Methylsulfonyl- und N-Phenylsulfonyl-N-methylhydroxylamin / N-Methylsulfonyl and N-Phenylsulfonyl N-methylhydroxylamine

1978 ◽  
Vol 33 (1) ◽  
pp. 125-126 ◽  
Author(s):  
Michael Backhaus ◽  
Claus Bliefert
Keyword(s):  
Alkaline Hydrolysis ◽  
Nmr Spectra ◽  
Hydroxamic Acids ◽  
H Nmr

Abstract N-Methylhydroxylamine, Hydroxamic Acids, Nitrosomethane, Formaldoxime N-Methylsulfonyl and N-phenylsulfonyl N-methylhydroxylamine, CH3SO2N(CH3)OH and C6H5SO2N(CH3)OH, result from the reactions of methylsulfonyl chloride and phenylsulfonyl chloride with N-methyl-hydroxylamine. The acid and alkaline hydrolysis, IR and 1H NMR spectra are reported.

Annelation to the Quinazoline Ring. Preparation of Some Substituted 2H-Imidazo- and 2,3-Dihydropyrimido[1,2-c]quinazolines

1996 ◽  
Vol 61 (6) ◽  
pp. 957-961 ◽  
Author(s):  
Katarína Špirková ◽  
Štefan Stankovský
Keyword(s):  
Amino Acid ◽  
Nmr Spectra ◽  
Amino Acid Esters ◽  
H Nmr ◽  
Acid Esters ◽  
C Nmr

Preparation of some substituted 2H-imidazo[1,2-c]quinazolin-3-ones (2a-2f) and 2,3-dihydropyrimido[1,2-c]quinazolin-4-ones (3a-3c) by reaction of corresponding 3H-quinazoline-4-thiones (1a-1d) with amino acid esters is described. IR, 1H NMR and 13C NMR spectra of the compounds synthesized are presented.

Conformational structure of ethylene glycol dibenzoate. Vibrational and NMR spectra

1981 ◽  
Vol 46 (8) ◽  
pp. 1913-1929 ◽  
Author(s):  
Bohdan Schneider ◽  
Pavel Sedláček ◽  
Jan Štokr ◽  
Danica Doskočilová ◽  
Jan Lövy
Keyword(s):  
Ethylene Glycol ◽  
Vibrational Spectra ◽  
Nmr Spectra ◽  
Coupling Constants ◽  
Conformational Structure ◽  
Infrared And Raman Spectra ◽  
H Nmr ◽  
Liquid States ◽  
Crystalline Forms ◽  
C Nmr

It was found that three crystalline forms of ethylene glycol dibenzoate can be prepared. Infrared and Raman spectra of these three forms, as well as of the glassy and liquid states, were measured. From 3JHH coupling constants obtained by analysis of the 13C satellite band of the -CH2- group in 1H NMR spectra, and from the 3JCH coupling constants of the -CO.O.CH2- fragment obtained by analysis of the carbonyl band in 13C NMR spectra it was found that in the liquid state the -CH2-CH2- group exists predominantly in the gauche conformational structure, and the bonds C-O-C-C assume predominantly a trans orientation. The results of the analysis of NMR and vibrational spectra were used for the structural interpretation of conformationally sensitive bands in vibrational spectra of ethylene glycol dibenzoate.

Preparation and absolute configuration at C(20) of 21-nor-5α-chol-22-en-24→20-olide derivatives

1981 ◽  
Vol 46 (4) ◽  
pp. 917-925 ◽  
Author(s):  
Vladimír Pouzar ◽  
Miroslav Havel
Keyword(s):  
Absolute Configuration ◽  
Nmr Spectra ◽  
Lithium Salt ◽  
H Nmr ◽  
Chemical Correlation ◽  
Unsaturated Lactones

Reaction of the aldehyde I with the lithium salt of 1-(2-tetrahydropyranyloxy)-2-propyne yielded the compounds II and IV. From the compound II the lactone XII was prepared via the intermediates III and X, the lactone XVIII was prepared from the substance IV via the intermediates V and XVI. The unsaturated lactones XII and XVIII were also prepared by sulfenylation and dehydrosulfenylation of the saturated lactones XIII and XIX. Based on chemical correlation and 1H-NMR spectra analyses of the compounds II and IV, the lactone XII was assigned the 20R-configuration whereas the lactone XVIII was allotted the 20S-configuration.

New type of addition to 5-substituted 4-arylidene-2-(4,5-dihydrofurfurylidene)-N,N-dimethyliminium bisperchlorates. Preparation of 4-substituted 5-(N,N-dimethylamino)-2-furancarbaldehydes

1986 ◽  
Vol 51 (3) ◽  
pp. 573-580 ◽  
Author(s):  
Tibor Gracza ◽  
Zdeněk Arnold ◽  
Jaroslav Kováč
Keyword(s):  
Nmr Spectra ◽  
Addition Reaction ◽  
H Nmr ◽  
Organic Bases ◽  
New Type

4-Arilidene-5-(N,N-dimethyliminium)-2-(4,5-dihydrofurfurylidene)-N,N-dimethyliminium bisperchlorate I undergoes a 1,4-addition reaction with organic bases under re-formation of the furan nucleus; this behaviour has been utilized in the preparation of new 4-substituted 5-(N,N-dimethylamino)-2-furancarbaldehydes II, III. The structure of the prepared compounds has been confirmed by 13C and 1H NMR spectra.

Preparation, properties and structure of some intermediate nido- and arachno-monocarbaboranes

1981 ◽  
Vol 46 (10) ◽  
pp. 2345-2353 ◽  
Author(s):  
Karel Baše ◽  
Bohumil Štíbr ◽  
Jiří Dolanský ◽  
Josef Duben
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Nmr Spectra ◽  
Liquid Ammonia ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Starting Compound

The 6-N(CH3)3-6-CB9H11 carbaborane reacts with sodium in liquid ammonia with the formation of 6-CB9H12- which was used as a starting compound for preparing the 4-CB8H14, 9-L-6-CB9H13 (L = (CH3)2S, CH3CN and P(C6H5)3), 1-(η5-C5H5)-1,2-FeCB9H10-, and 2,3-(η5-C5H5)2-2,31-Co2CB9H10- carboranes. The 4-CB8H14 compound was dehydrogenated at 623 K to give 4-(7)-CB8H12 carborane. Base degradation of 6-N(CH3)3-6-CB9H11 in methanol resulted in the formation of 3,4-μ-N(CH3)3CH-B5H10. The structure of all compounds was proposed on the basis of their 11B and 1H NMR spectra and X-ray diffraction was used in the case of the transition metal complexes.

The preparation of 3-amino-3-deoxy-1,2-O-isopropylidene-α-L-erythrofuranose, 3-amino-3-deoxy-1,2-O-isopropylidene-β-D-threofuranose and their derivatives

1980 ◽  
Vol 45 (12) ◽  
pp. 3378-3390 ◽  
Author(s):  
Jiří Jarý ◽  
Milena Masojídková ◽  
Ivan Kozák ◽  
Miroslav Marek ◽  
Jan Staněk
Keyword(s):  
Nucleophilic Substitution ◽  
Sodium Azide ◽  
Sodium Benzoate ◽  
Nmr Spectra ◽  
Subsequent Reduction ◽  
H Nmr ◽  
Amino Derivatives

The title amino derivatives VI and XIV were prepared by nucleophilic substitution of p-toluenesulfonyl derivatives II and XVII with sodium azide or hydrazine and subsequent reduction. Nucleophilic substitution of compounds II and XVII with sodium benzoate was also investigated. The 1H NMR spectra of the substances prepared are discussed.

Preparation of (20E)-21-Ethoxycarbonyl-14β,17α-pregna-5,20-dien-3β-yl Hydrogen Butanedioate

1995 ◽  
Vol 60 (4) ◽  
pp. 715-718 ◽  
Author(s):  
Vladimír Pouzar ◽  
Ivan Černý
Keyword(s):  
Title Compound ◽  
Nmr Spectra ◽  
Total Yield ◽  
Reaction Sequence ◽  
Pregnane Series ◽  
H Nmr

The title compound X was prepared according to the recently published procedure for preparation of analogous derivatives in the 5β-pregnane series, using the reaction sequence I -> II -> III -> IV -> V -> VI -> VII -> VII -> IX -> X (total yield 18%). The configuration at ring D centers (14β,17α) follows from the structure of the starting ketone I and was also checked by comparing diol IV with the sample prepared by an independent route. The epimeric purity at C-17 was carefully monitored during the whole synthesis by 1H NMR spectra (singlet of 18-H3).

Axially Chiral Bis(α-amino Acid)s and Their Deamino Analogues. Synthesis and Configurational Assignment

1998 ◽  
Vol 63 (2) ◽  
pp. 211-221 ◽  
Author(s):  
Miloš Tichý ◽  
Luděk Ridvan ◽  
Miloš Buděšínský ◽  
Jiří Závada ◽  
Jaroslav Podlaha ◽  
...  
Keyword(s):  
Amino Acid ◽  
Nmr Spectra ◽  
Building Blocks ◽  
X Ray Diffraction ◽  
Amino Groups ◽  
X Ray ◽  
Configurational Assignment ◽  
Symmetry Properties ◽  
Axially Chiral ◽  
Polymeric Structures

The axially chiral bis(α-amino acid)s cis-2 and trans-2 as possible building blocks for polymeric structures of novel type of helicity were prepared. Their configuration has been determined by NMR spectroscopy and, in the case of the trans-isomer, confirmed by single-crystal X-ray diffraction. Analogous pair of stereoisomeric diacids cis-3 and trans-3, devoid of the amino groups, was also prepared and their configuration assigned. The observed differences in the NMR spectra of cis- and trans-isomers of 2 and 3 are discussed from the viewpoint of their different symmetry properties.

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