The preparation of amino sugars and branched-chain sugars by palladium-catalyzed, allylic substitution of alkyl hex-2-enopyranosides

1981 ◽  
Vol 59 (5) ◽  
pp. 889-906 ◽  
Author(s):  
Hans H. Baer ◽  
Zaher S. Hanna
Keyword(s):  
Mass Spectra ◽  
Nmr Spectra ◽  
Optical Rotation ◽  
New Products ◽  
Catalytic Amount ◽  
Amino Sugars ◽  
H Nmr ◽  
Palladium Catalyzed ◽  
Branched Chain ◽  
High Yields

Ethyl 4,6-di-O-acetyl-2,3-dideoxy-α-D-erythro-hex-2-enopyranoside (1) in the presence of triphenylphosphine and a catalytic amount of tetrakis(triphenylphosphine)palladium(0) reacted with a variety of amines or with reactive methylene compounds to give high yields of products aminated or C-alkylated, respectively, in an allylic position. Some analogous experiments were performed using the β-D-erythro anomer (2) and the α-D-threo epimer (3) of 1. The constitutions and configurations of the new products were established by means of mass spectra, 13C- and 1H-nmr spectra, and optical rotation data. The reactions of 1 were found to be highly regio- and stereoselective, giving almost exclusively 4-substituted 2-enopyranosides with retention of configuration, except in the case of dibenzylamine which produced a mixture of the corresponding enoside and its 2-substituted, 3,4-unsaturated isomer having the α-D-threo configuration. The reactions of 2 appeared slightly less selective although they, too, furnished mainly 4-substituted 2-enopyranosides with retention of configuration. Regioselectivity was low or lacking in two C-alkylations performed with 3, which gave mixtures of 4-substituted 2-enosides and 2-substituted 3-enosides. Some aspects of conformation and optical rotation in enopyranosides are discussed.

scholarly journals Metallkomplexe mit Tetrapyrrol-Liganden, XXXVIII [1]. Zur Kenntnis der Alkyl- und Arylimidovanadium(IV)-Porphyrine / Metal Complexes with Tetrapyrrole Ligands, XXXVIII [1]. On the Knowledge of Alkyl- and Arylimidovanadium(IV) Porphyrins

1985 ◽  
Vol 40 (10) ◽  
pp. 1362-1370 ◽  
Author(s):  
Johann W. Buchler ◽  
Stefan Pfeifer
Keyword(s):  
Mass Spectra ◽  
Nmr Spectra ◽  
Primary Amines ◽  
Reactive Intermediate ◽  
H Nmr ◽  
Vanadyl Complex ◽  
Elemental Analyses ◽  
Paramagnetic Metal ◽  
Paramagnetic Complexes ◽  
Proton Resonances

A series of novel alkyl or aryiimidovanadium(IV) 5,10,15,20-tetra(p-tolyl)porphyrinates, VNR(TTP) (4a-4g), is described. They are obtained from the vanadyl complex, VO(TTP) (2a) via the reactive intermediate VCl2(TTP) (3b) which undergoes aminolysis with the respective primary amines RNH2 (R = tBu, Ph, pTol, pClPh, pAnis, pBiph, ptBuPh)**. The formulae are proved by elemental analyses and mass spectra. The paramagnetic complexes are stable to water and may thus be purified by chromatography but are hydrolyzed to give 2 a on treatment with acetic acid. The UV/VIS and 1H NMR spectra of 4a-4g are of the same type as 2a, but the former are slightly hypsochromically shifted, and the latter do not show the proton resonances of the organylimide ligands due to the proximity of the paramagnetic metal center.

X-Ray Structure Analysis and Spectroscopic Data of the Antibiotic 8-(Dichloroacetyl)-5-hydroxy-2,7-dimethyl-1,4-naphthoquinone from the Fungus Mollisia sp.*

1987 ◽  
Vol 42 (1-2) ◽  
pp. 1-3 ◽  
Author(s):  
Gabriela Weber ◽  
Thomas Hübner ◽  
Alfred Gieren ◽  
Johann Sonnenbichler ◽  
Tadeusz Kowalski ◽  
...  
Keyword(s):  
High Resolution ◽  
Structure Analysis ◽  
Spectroscopic Data ◽  
Mass Spectra ◽  
Nmr Spectra ◽  
X Ray ◽  
H Nmr

Abstract Mass spectra, X-ray data and high resolution 13C and 1H NMR spectra of 8-(dichloroacetyl)-5-hydroxy-2,7-dim ethyl-1,4-naphthoquinone are reported. The antibiotic active com pound was isolated from the fungus Mollisia sp.

Synthese und Konformationsstudien ringsubstituierter Titanocen-Dithiolen-Chelate / Synthesis and Conform ational Studies of Ring-Substituted Titanocene Dithiolene Chelates

1986 ◽  
Vol 41 (6) ◽  
pp. 667-670 ◽  
Author(s):  
Hartmut Köpf ◽  
Thomas Klapötke
Keyword(s):  
Mass Spectra ◽  
Nmr Spectra ◽  
Chelating Ligands ◽  
Temperature Dependent ◽  
H Nmr ◽  
Fragmentation Processes

Abstract The titanocene dithiolenato chelates Cp′2Ti(S2C6H3CH3-4) and CpCp′Ti(S2C6H3CH3-4) (Cp = η5-C5H5, Cp′ = η5-C5H4CH3) were prepared by reaction o f Cp′2TiCl2 or CpCp′TiCl2 with equiva­lent amounts of 1,2 -(LiS)2C6H3CH3-4. The structure and the conform ational mobility of the η5-bonded and of the chelating ligands of the dithiolenato complexes are discussed on the basis of their temperature-dependent 1H NMR spectra. The mass spectra show metastable transitions for the fragmentation processes.

scholarly journals SYNTHESIS OF SOME FLAVONES AND 4-THIOFLAVONES AS POTENT ANTIBACTERIAL AGENTS

2009 ◽  
Vol 12 (3) ◽  
pp. 33-39
Author(s):  
Ha Tuong Do ◽  
Dao Thanh Tran
Keyword(s):  
Dimethyl Sulfoxide ◽  
Potassium Hydroxide ◽  
Nmr Spectra ◽  
Room Temperature ◽  
Antibacterial Agents ◽  
Synthetic Compounds ◽  
H Nmr ◽  
High Yields ◽  
Benzaldehyde Derivatives ◽  
Boiling Toluene

A series of flavones and thioflavones were synthesized via the chalcone pathway, in which 2'-hydroxyacetophenone is condensed with benzaldehyde derivatives in the medium of potassium hydroxide - methanol at room temperature. The obtained chalcones were treated by iodine in refluxed dimethyl sulfoxide turning into the corresponding flavones. Reaction of flavones and Lawesson's reagent in boiling toluene gave the 4-thioflavones with high yields from 53-76%. All the synthetic compounds were purified by column chromatography and recorded their UV, IR and 'H-NMR spectra.

Preparation of C(18)-empiric 20,29,30-trinorlupane derivatives. 1H, 13C NMR and mass spectra

1986 ◽  
Vol 51 (3) ◽  
pp. 621-635 ◽  
Author(s):  
Václav Křeček ◽  
Jiří Protiva ◽  
Miloš Buděšínský ◽  
Eva Klinotová ◽  
Alois Vystrčil
Keyword(s):  
Nitrous Acid ◽  
Mass Spectra ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Allylic Oxidation ◽  
Hydroxyl Group ◽  
Methyl Groups ◽  
Unsaturated Ketone ◽  
H Nmr ◽  
C Nmr

Reaction of amide I with nitrous acid gave the olefins II, III and IV. On allylic oxidation of olefin IV α,β-unsaturated ketone V is formed from which olefins VIII and IX were prepared by a sequence of further reactions. Addition of hydrogen to the double bond of olefin IV and α,β-unsaturated ketone V takes place on catalytic hydrogenation from the β-side and leads to derivatives with cis-annellated rings D/E. This made the preparation of hydrocarbons VI and VII epimeric on C(18) possible, which represent reference compounds for the study of the effect of substituents on the chemical shifts of the methyl groups and the saturated carbon atoms of 18αH and 18βH-lupane derivatives. The configuration of the hydroxyl group in epimers XI and XII were derived from 1H NMR spectra. Deuteration of olefins III, IV and IX gave deuteriohydrocarbons XVI to XVIII. The 1H, 13C NMR and mass spectra of the substances prepared are discussed.

The synthesis of uridine diphosphate N-acetylhexosamines and uridine 5′-(2-acetamido-2-deoxy-α-D-mannopyranosyluronic acid diphosphate)

1981 ◽  
Vol 59 (15) ◽  
pp. 2247-2252 ◽  
Author(s):  
Tatsumi Yamazaki ◽  
Christopher D. Warren ◽  
Annette Herscovics ◽  
Roger W. Jeanloz
Keyword(s):  
Platinum Catalyst ◽  
Optical Rotation ◽  
Exchange Chromatography ◽  
High Yield ◽  
Uridine Diphosphate ◽  
Nmr Spectrum ◽  
H Nmr ◽  
Catalytic Hydrogenolysis ◽  
High Yields ◽  
Biosynthetic Studies

2-Methyl-(2-acetamido-3,4,6-tri-O-acetyl-l,2-dideoxy-β-D-mannopyrano)-[2,1-d]-2-oxazoline was efficiently converted into 2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-α-D-mannopyranosyl phosphate, by treatment with dibenzyl phosphate, followed by catalytic hydrogenolysis of the benzyl groups. Similarly, 2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-α-D-glucopyranosyl phosphate and -galactopyranosyl phosphate were synthesized from the respective peracetyl oxazolines. In each case, the procedures for preparing the oxazoline, and conversion into the glycosyl phosphate, were modified to give high yields of pure products. 2-Acetamido-3,4,6-tri-O-acetyl-2-deoxy-α-D-mannopyranosyl phosphate was coupled with 2′,3′-di-O-acetyluridine 5′-monophosphate by a modification of the mixed anhydride procedure, to give 2',3'-di-O-acetyluridine 5′-(2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-α-D-mannopyranosyl diphosphate), which was readily purified by preparative tic and O-deacetylated to give "uridine diphosphate N-acetylmannosamine" in high yield. Similarly, uridine 5′-(2-acetamido-2-deoxy-α-D-glucopyranosyl- and -galactopyranosyl diphosphates) were synthesized by rapid, efficient procedures, not involving ion-exchange chromatography. Uridine 5′-(2-acetamido-2-deoxy-α-D-mannopyranosyl diphosphate) was converted into uridine 5′-(2-acetamido-2-deoxy-α-D-mannopyranosyluronic acid diphosphate), required for biosynthetic studies, without the preparation of a special platinum catalyst. All the synthetic uridine diphosphate sugars were characterized by optical rotation, 1H nmr spectrum, and elemental analysis.

scholarly journals Synthesis, Characterization and Antibacterial Activity of Schiff Bases and their Metal Complexes Derived from 4-Acyl-1-phenyl-3-methyl-2-pyrazolin-5-ones and 2-Amino-4(4'-methylphenyl)-thiazole

2010 ◽  
Vol 7 (4) ◽  
pp. 1396-1406 ◽  
Author(s):  
A. S. Thakar ◽  
K. K. Singh ◽  
K. T. Joshi ◽  
A. M. Pancholi ◽  
K. S. Pandya
Keyword(s):  
Antibacterial Activity ◽  
Schiff Bases ◽  
Elemental Analysis ◽  
Mass Spectra ◽  
Nmr Spectra ◽  
Electrical Conductance ◽  
H Nmr ◽  
Infrared Spectral ◽  
Ft Ir ◽  
C Nmr

4-Acyl-1-phenyl-3-methyl-2-pyrazolin-5-ones condensed with 2-amino-4(4'-methylphenyl)-thiazole to form Schiff base. These Schiff bases from complexes of type ML22H2O (M=Mn, Fe, Co, Ni and Cu). Elemental analysis, magnetic susceptibility, electrical conductance, electronic and Infrared spectral data suggested octahedral structure for the complexes. All the compounds were tested for their antibacterial activity. The result indicates that the growth of the tested organism was inhibited by most of the compounds. These Schiff bases are characterized by elemental analysis, mass spectra,1H-NMR spectra,13C NMR spectra and FT IR spectra.

Synthesis of Some 2-Aminonitroethanes via Silica Gel-Catalyzed Nitro-Mannich Reaction

2006 ◽  
Vol 61 (9) ◽  
pp. 1162-1165 ◽  
Author(s):  
Ali S. Mahasneh
Keyword(s):  
Silica Gel ◽  
Elemental Analysis ◽  
Mannich Reaction ◽  
Nmr Spectra ◽  
One Pot ◽  
H Nmr ◽  
High Yields ◽  
C Nmr

Abstract A direct one pot, three-component nitro-Mannich reaction of a nonenolizable aldehyde, aniline or one of its ring-substituted derivatives and nitromethane was carried out on silica gel surface. The products of the reaction, 2-aminonitroethane, were obtained in high yields. IR, 1H NMR, 13C NMR spectra and elemental analysis confirmed the structures of the products.

Photochemische Reaktionen von Übergangsmetall-Olefin-Komplexen, II Die Umsetzung von Tricarbonyl-η-1.3.5-cycloheptatrien-chrom(O) mit substituierten Fulvenen /Photochemical Reactions of Transition Metal Olefin Complexes, II The Reaction of Tricarbonyl-η-1,3,5-cycloheptatriene-chromium(O) with Substituted Fulvenes

1978 ◽  
Vol 33 (11) ◽  
pp. 1285-1290 ◽  
Author(s):  
Cornelius G. Kreiter ◽  
Hans Kurz
Keyword(s):  
Transition Metal ◽  
Mass Spectra ◽  
Nmr Spectra ◽  
Uv Light ◽  
Photochemical Reactions ◽  
The Other ◽  
Chelate Ligand ◽  
Chromium Complex ◽  
High Yields ◽  
C Nmr

Abstract When tricarbonyl-η-1,3,5-cycloheptatriene-chromium(O) (1) and 6,6-dimethylfulvene or tricarbonyl-η-6,6-dimethylfulvene-chromium(O) and 1,3,5-cyeloheptatriene are irradiated with UV light, a red crystalline dicarbonyl-chromium complex with an η3 -1′,2′,3′-(2-cyclohepta-2′, 4′ -dien 1′ ,6′-ylene)-η5 (2-cyclopentadienylidene)propane chelate ligand, Cr(CO)2C15H18 (2), is formed in high yields. Under the same conditions, 1 with 6,6-diphenylfulvene yields two isomeric complexes. One of them, Cr(CO)3C25H22 (3), is analoguous to 2 and contains the η3 -1′,2′,3′-cyclohepta-2′,4′-dien-1′ ,6′ / -ylene-η5 -cyclopentadienylidene-diphenyl-methane chelate ligand. The other one is the dicarbonyl η3 -1′,2′,3′-cyclohep-tatrienyl- η5 diphenylmethylcyclopentadienyl-chromium(O), Cr(CO)2(C7H7)(Ci8H15) (4). The complexes were characterized by analysis and mass spectra. The structures are based on IR, and 1H and 13C NMR spectra. Einführung

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