SYNTHESIS OF METHYL 4-ACETAMIDO-4-DEOXY-L-ERYTHROFURANOSIDE: A SUGAR WITH NITROGEN IN A FIVE-MEMBERED RING

1964 ◽  
Vol 42 (1) ◽  
pp. 20-24 ◽  
Author(s):  
W. A. Szarek ◽  
J. K. N. Jones
Keyword(s):  
Structural Features ◽  
Membered Ring

The synthesis of methyl 4-acetamido-4-deoxy-L-erythrofuranoside from D-ribose is described. The structural features that are believed to be necessary for the replacement of the ring oxygen of sugars by nitrogen are discussed.

scholarly journals SÍNTESE DE NOVOS 1,2,3-TRIAZÓIS INSPIRADOS NO SRPIN340 E AVALIAÇÃO DE SEUS EFEITOS EM LINHAGEM CELULAR DE GLIOBLASTOMA HUMANO

Química Nova ◽  
2021 ◽  
Author(s):  
Sara Sousa ◽  
Róbson Teixeira ◽  
Adilson Costa ◽  
Alex Aguiar ◽  
Victor Fonseca ◽  
...  
Keyword(s):  
Cell Viability ◽  
Cell Line ◽  
Treatment Time ◽  
Cycloaddition Reaction ◽  
Structural Features ◽  
Biological Evaluation ◽  
Membered Ring ◽  
Glioblastoma Cell Line ◽  
Human Glioblastoma ◽  
Human Glioblastoma Multiforme

SYNTHESIS OF NOVEL 1,2,3-TRIAZOLES INSPIRED ON THE SRPIN340 AND EVALUATION OF THEIR EFFECTS ON HUMAN GLIOBLASTOMA CELL LINE. It is herein described the synthesis of a series of thirty novel 1,2,3-triazole1,4-disubstituted compounds inspired on the known SRPKs inhibitor N-(2-(piperidin-1-yl)-5-(trifluoromethyl)phenyl)isonicotinamide (SRPIN340) and biological evaluation of them against human glioblastoma multiforme cell line U87MG. Starting with 1-fluoro2-nitro-4- (trifluoromethyl)benzene (1), the substances were prepared via a five-step synthetic route. The crucial step corresponded to the copper-catalyzed cycloaddition reaction between trifluoromethyl phenyl azides and different alkynes. In general, the compounds were obtained with good yields and they were characterized utilizing spectroscopic (IR and NMR) and spectrometric (HRMS) techniques. The evaluation of the synthesized compounds at three different treatment time (24 h, 48 h, and 72 h) and concentrations (50, 100, and 150 µmol L-1) revealed that five derivatives were capable of reducing cell viability by 50% after 72 h of treatment at the highest concentration. On the contrary, three derivatives significantly increased cell viability being this effect more pronounced after 48 h of treatment. In this regard, it stands out the compound 2-((1-(2-morpholino-5-(trifluoromethyl)phenyl)-1H-1,2,3-triazol4-yl)methyl)isoindoline-1,3-dione (7) which increased cell viability in approximately 300% after 48 h of treatment at 100 µmol L-1. The substances that increased cell viaiblity present as common structural features the presence of a saturated nitrogen-containing six-membered ring and carbonylated fragments.

scholarly journals Mimicking Noncanonical Oxidations with Redox-Neutral Photocatalysis

2019 ◽  
Author(s):  
Zheng Huang ◽  
Jean-Philip Lumb
Keyword(s):  
Organic Synthesis ◽  
Structural Features ◽  
Membered Ring ◽  
Ring Formation ◽  
Radical Cyclizations ◽  
General Strategy ◽  
Sufficient Time ◽  
Lignan Biosynthesis

Noncanonical oxygenases are a family of Fe-containing enzymes that catalyze oxidative radical cyclizations. Despite creating key structural features that often define a natural product’s complexity, the mechanisms of these oxidations remain poorly understood and difficult to mimic. In this work, we show that noncanonical cyclizations from lignan biosynthesis can be recreated when presumed biosynthetic radicals are generated using photocatalysis. These conditions afford the ensuing electron rich radicals sufficient time to undergo challenging 5- or 11-membered ring formation that create the defining structural features of the highly oxidized lignans taiwankadsurins A, B and kadsuphilin N. By showing that these cyclizations can occur without enzymatic assistance, we provide a more general strategy for mimicking noncanonical transformations that should broaden their use in organic synthesis.

Interplay between steric and electronic factors in determining the strength of intramolecular N—H...O resonance-assisted hydrogen bonds in β-enaminones

2006 ◽  
Vol 62 (6) ◽  
pp. 1112-1120 ◽  
Author(s):  
Valerio Bertolasi ◽  
Loretta Pretto ◽  
Valeria Ferretti ◽  
Paola Gilli ◽  
Gastone Gilli
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Structural Features ◽  
Membered Ring ◽  
Resonance Assisted Hydrogen Bond ◽  
Electronic Resonance ◽  
Hydrogen Bonded

The crystal structures of five β-enaminones are reported: (2Z)-3-(benzylamino)-1,3-diphenyl-prop-2-en-1-one, (2Z)-3-(benzylamino)-3-(2-hydroxyphenyl)-1-phenyl-prop-2-en-1-one, (2Z)-3-(benzylamino)-3-(4-methoxyphenyl)-1-(3-nitrophenyl)-prop-2-en-1-one, 2-{1-[(4-methoxyphenyl)amino]ethylidene}cyclohexene-1,3-dione and 2-{1-[(3-methoxyphenyl)amino]ethylidene}cyclohexene-1,3-dione. The structures were analysed and compared with those of similar compounds in order to establish which factors determine the range (2.53–2.72 Å) of N...O hydrogen-bond distances in intramolecularly hydrogen-bonded β-enaminones. It has been shown that, beyond electronic resonance-assisted hydrogen-bond effects modulated by substituents, the necessary requirements to produce very short N—H...O hydrogen bonding are steric intramolecular repulsions, including the embedding of an enaminonic C—C or C—N bond in an aliphatic six-membered ring. By considering the structural features it is possible to expect the strength of N—H...O hydrogen bonds adopted by specific β-enaminones.

THE CARBONYL STRETCHING BANDS IN THE INFRARED SPECTRA OF UNSATURATED LACTONES

1959 ◽  
Vol 37 (12) ◽  
pp. 2007-2022 ◽  
Author(s):  
R. N. Jones ◽  
C. L. Angell ◽  
T. Ito ◽  
R. J. D. Smith
Keyword(s):  
Infrared Spectra ◽  
Carbonyl Compounds ◽  
Structural Features ◽  
Membered Ring ◽  
Fermi Resonance ◽  
Fundamental Vibration ◽  
Conformational Isomers ◽  
Band Splitting ◽  
Carbonyl Band ◽  
Unsaturated Lactones

Certain types of unsaturated lactones exhibit two bands in the region of the spectrum associated with the C=O stretching vibrational mode. This is observed both in the infrared and Raman spectra.The infrared spectra of 23 simple saturated and unsaturated lactones have been examined in an attempt to determine the structural features with which this carbonyl band splitting is associated. It appears to be common to most unsaturated five- and six-membered ring lactones in which the double bond is conjugated with the carbonyl group, though one well-established exception has been observed. The relative intensities of the two bands are extremely sensitive to changes in the polarity of the solvent; they also vary reversibly with temperature but are independent of concentration.The splitting of the C=O stretching band is attributed to an intramolecular vibrational effect similar to that which occurs in cyclopentanone and in certain Δ2-cyclopentenone derivatives. Its possible dependence on Fermi resonance with the overtone of a lower lying fundamental vibration is discussed.Similar effects occur in other types of carbonyl compounds, such as benzoyl chloride and cyclic five-membered ring anhydrides, and care is needed to distinguish carbonyl band splitting of this kind from that associated with equilibria between conformational isomers.

scholarly journals Mimicking Noncanonical Oxidations with Redox-Neutral Photocatalysis

2019 ◽  
Author(s):  
Zheng Huang ◽  
Jean-Philip Lumb
Keyword(s):  
Organic Synthesis ◽  
Structural Features ◽  
Membered Ring ◽  
Ring Formation ◽  
Radical Cyclizations ◽  
General Strategy ◽  
Sufficient Time ◽  
Lignan Biosynthesis

Noncanonical oxygenases are a family of Fe-containing enzymes that catalyze oxidative radical cyclizations. Despite creating key structural features that often define a natural product’s complexity, the mechanisms of these oxidations remain poorly understood and difficult to mimic. In this work, we show that noncanonical cyclizations from lignan biosynthesis can be recreated when presumed biosynthetic radicals are generated using photocatalysis. These conditions afford the ensuing electron rich radicals sufficient time to undergo challenging 5- or 11-membered ring formation that create the defining structural features of the highly oxidized lignans taiwankadsurins A, B and kadsuphilin N. By showing that these cyclizations can occur without enzymatic assistance, we provide a more general strategy for mimicking noncanonical transformations that should broaden their use in organic synthesis.

Hetero[8]circulenes: synthetic progress and intrinsic properties

2020 ◽  
Vol 56 (100) ◽  
pp. 15605-15614
Author(s):  
Yoshihiro Miyake ◽  
Hiroshi Shinokubo
Keyword(s):  
Structural Features ◽  
Membered Ring ◽  
Synthetic Route ◽  
Intrinsic Properties ◽  
Ring Fusion ◽  
Electronic Nature ◽  
Peripheral Ring

Synthetic route for hetero[8]circulenes are classified into the annulative construction of eight-membered ring and the peripheral ring fusion of eight-membered ring. Post-transformation enables the tuning of structural features and electronic nature.

Structural Features in the Seven-Membered vs. Fourteen-Membered Ring Cyclization of Hydroxyamido Ketals Derived from β-Amino Alcohols

2001 ◽  
Vol 2001 (11) ◽  
pp. 2041-2053 ◽  
Author(s):  
Anne-Gaëlle Valade ◽  
Denise Dugat ◽  
Georges Jeminet ◽  
Jacques Royer ◽  
Henri-Philippe Husson
Keyword(s):  
Amino Alcohols ◽  
Structural Features ◽  
Membered Ring

scholarly journals Studies on the interaction of isocyanides with imines: reaction scope and mechanistic variations

2014 ◽  
Vol 10 ◽  
pp. 12-17 ◽  
Author(s):  
Ouldouz Ghashghaei ◽  
Consiglia Annamaria Manna ◽  
Esther Vicente-García ◽  
Marc Revés ◽  
Rodolfo Lavilla
Keyword(s):  
Double Bond ◽  
Lewis Acid ◽  
Acid Catalysis ◽  
Main Product ◽  
Structural Features ◽  
Ring System ◽  
Membered Ring ◽  
Sequential Process ◽  
Lewis Acid Catalysis ◽  
Nitrogen Double Bond

The interaction of imines with isocyanides has been studied. The main product results from a sequential process involving the attack of two units of isocyanide, under Lewis acid catalysis, upon the carbon–nitrogen double bond of the imine to form the 4-membered ring system. The scope of the reaction regarding the imine and isocyanide ranges has been determined, and also some mechanistic variations and structural features have been described.

scholarly journals Different packing motifs mediated by weak interactions and polymorphism in the crystal structures of five 2-(benzylidene)benzosuberone derivatives

2019 ◽  
Vol 75 (11) ◽  
pp. 1741-1747
Author(s):  
Lewis S. Seaman ◽  
Cristiane F. da Costa ◽  
Marcus V. N. de Souza ◽  
Solange M. S. V. Wardell ◽  
James L. Wardell ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Benzene Ring ◽  
Weak Interactions ◽  
Structural Features ◽  
Membered Ring ◽  
Dihedral Angles ◽  
Π Interactions ◽  
Hirshfeld Surfaces ◽  
Key Features

The syntheses and crystal structures of five 2-benzylidene-1-benzosuberone [1-benzosuberone is 6,7,8,9-tetrahydro-5H-benzo[7]annulen-5-one] derivatives, viz. 2-(4-methoxybenzylidene)-1-benzosuberone, C19H18O2, (I), 2-(4-ethoxybenzylidene)-1-benzosuberone, C20H20O2, (II), 2-(4-benzylbenzylidene)-1-benzosuberone, C25H22O2, (III), 2-(4-chlorobenzylidene)-1-benzosuberone, C18H15ClO, (IV) and 2-(4-cyanobenzylidene)-1-benzosuberone, C19H15NO, (V), are described. The conformations of the benzosuberone fused six- plus seven-membered ring fragments are very similar in each case, but the dihedral angles between the fused benzene ring and the pendant benzene ring differ somewhat, with values of 23.79 (3) for (I), 24.60 (4) for (II), 33.72 (4) for (III), 29.93 (8) for (IV) and 21.81 (7)° for (V). Key features of the packing include pairwise C—H...O hydrogen bonds for (II) and (IV), and pairwise C—H...N hydrogen bonds for (V), which generate inversion dimers in each case. The packing for (I) and (III) feature C—H...O hydrogen bonds, which lead to [010] and [100] chains, respectively. Weak C—H...π interactions consolidate the structures and weak aromatic π–π stacking is seen in (II) [centroid–centroid separation = 3.8414 (7) Å] and (III) [3.9475 (7) Å]. A polymorph of (I) crystallized from a different solvent has been reported previously [Dimmock et al. (1999) J. Med. Chem. 42, 1358–1366] in the same space group but with a packing motif based on inversion dimers resembling that seen in (IV) in the present study. The Hirshfeld surfaces and fingerprint plots for (I) and its polymorph are compared and structural features of the 2-benzylidene-1-benzosuberone family of phases are surveyed.

Sign in / Sign up

Export Citation Format

Share Document