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  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of organic chemistry 56 (1991), S. 3591-3594 
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of medicinal chemistry 37 (1994), S. 73-77 
    ISSN: 1520-4804
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1520-4804
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of organic chemistry 58 (1993), S. 5994-5999 
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1434-4475
    Keywords: Michael type addition ; L-Nucleosides ; 2′,3′,6′-Trideoxy-L-hexofuranose nucleosides ; 3′-(1,2,4-Triazol-1-yl) nucleosides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die quecksilberkatalysierte Hydrolyse von acetyliertemL-Rhamnal1 ergab die α,β-ungesättigten Aldehyde2. 1,2,3-Triazol wurde in Gegenwart von 1,8-Diazabicyclo[5.4.0]-7-undecen mittels einer Addition vom Michael-Typ an C-3 von2 gekoppelt und ergab dann nach Acetylierung am anomeren Zentrum eine anomere Mischung von 1,5-Di-O-acetyl-3-(1,2,4-triazol-1-yl)-2,3,6-trideoxy-L-arabino-hexofuranose (3). Die Reaktion von3 mit silyliertem 2,4-Di-hydroxypyrimidinen4 in Gegenwart von Trimethylsilyltriflat in absolutem Ethanol ergab die entsprechenden Nucleoside7 und8.
    Notes: Summary Mercuric catalyzed hydrolysis of acetylatedL-rhamnal1 gave the α,β-unsaturated aldehyde2. 1,2,4-Triazole was coupled, in a Michael type addition reaction, to2 at C-3 in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) to give, after acetylation at the anomeric center, an anomeric mixture of 1,5-di-O-acetyl-3-(1,2,4-triazol-1-yl)-2,3,6-trideoxy-L-arabino-hexofuranose (3). Reaction of3 with silylated 2,4-dihydroxypyrimidines4 in the presence of trimethylsilyl triflate as catalyst followed by deprotection with 33% methylamine in absolute ethanol afforded the corresponding nucleosides7 and8.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1434-4475
    Keywords: 3′-Azido-2′,3′-dideoxy-2-thiouridines ; 5-Alkoxy-2-thiouracils ; Nucleoside synthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die Reaktion von 3-Azido-5-O-tert-butyldiphenylsilyl-2,3-dideoxy-D-erythro-pentofuranosid (5) mit silyliertem 2-Thiouracil und 5-Alkoxy-2-thiouracil in Gegenwart von Trimethylsilyltrifluormethansulfonat ergab eine anomere Mischung der entsprechenden 3′-Azido-2′,3′-dideoxy-2-thiouridin-Derivate, wobei das α-Anomer das Hauptprodukt darstellte. Die ungeschützten Nucleoside wurden mittels Behandlung mit Tetrabutylammoniumfluorid erhalten.
    Notes: Summary Reaction of 3-azido-5-O-tert-butyldiphenylsilyl-2,3-dideoxy-D-erythro-pentofuranoside (5) with silylated 2-thiouracil and 5-alkoxy-2-thiouracils in the presence of trimethylsilyl trifluoromethanesulfonate afforded an anomeric mixture of the corresponding 3′-azido-2′,3′-dideoxy-2-thiouridine derivatives with the α-anomer as the main product. Deprotected nucleosides were obtained by treatment with tetrabutylammonium fluoride.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1434-4475
    Keywords: Nucleosides, convergent synthesis of ; Uridines, 3′-azido-2′,3′-dideoxy ; Uridines, 3′-fluoro-2′,3′-dideoxy ; AZT analogues ; Human immunodeficiency virus ; Herpes simplex virus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Aus Uracil (8) wurden in einer Mannich-Reaktion in 65–85% Ausbeute die 5-substituierten Dialkylaminomethyluracile11a–f hergestellt. Verbindungen11a–f wurden mit Hexamethyldisilazan silyliert und mit 2,3-Didesoxy-3-fluor-D-erythro-pentofuranosid (4) und 3-Azido-2,3-didesoxy-D-erythro-pentofuranosid (7) unter Verwendung von Trimethylsilyl-trifluormethansulfonat als Katalysator zu den entsprechenden 3′-Fluor-2′,3′-didesoxynucleosiden13a–f und 3′-Azido-2′,3′-didesoxynucleosiden16d, f umgesetzt. Deprotektion der 5-O-(4-Phenylbenzoyl)- geschützten Nucleoside13a–f und16d, f mit gesättigtem methanolischem Ammoniak und Trennung mittels Chromatographie ergab die neuen 2′,3′-Didesoxy-3′-fluoruridine14a–f und15a–f, sowie die 2′,3′-Didesoxy-3′-azidouridine17d, f und18d, f.
    Notes: Summary Uracil (8) was substituted in a Mannich reaction to give the 5-substituted dialkylamino-methyluracils11a–f in 65–85% yield. Compounds11a–f were silylated with hexamethyldisilazane and coupled with 2,3-dideoxy-3-fluoro-D-erythro-pentofuranoside4 and 3-azido-2,3-dideoxy-D-erythro-pentofuranoside7 to give the corresponding 3′-fluoro-2′,3′-dideoxynucleosides13a–f and 3′-azido-2′,3′-dideoxy nucleosides16d, f, respectively, by using trimethylsilyl trifluoromethanesulfonate as a catalyst. Deprotection of the 5-O-(4-phenylbenzoyl) protected nucleosides13a–f and16d, f with saturated methanolic ammonia and separation by chromatography yielded the new derivatives of 2′,3′-dideoxy-3′-fluorouridines14a–f and15a–f and 2′,3′-dideoxy-3′-azidouridines17d, f and18d, f.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1434-4475
    Keywords: Nucleosides, 2′,3′-dideoxy-3′-mercapto ; Nucleosides, 2′,3′-dideoxy-3′-methylthio ; Nucleosides 2′,3′-didehydro-2′,3′-dideoxy ; Disulfide, bis(2′,3′-dideoxy-nucleosid-3′-yl)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die in drei Stufen aus 2-Desoxy-D-ribose hergestellten Jodide4(α) bzw. 7 wurden einer Reihe von nucleophilen Substitutionsreaktionen unterzogen, wobei die 3-Benzoylthio-, 3-Methylthio-und 3-Thiocyanato-2,3-didesoxy-D-erythro-pentofuranoside8,13 und15 zusätzlich zum Disulfid17 ihrer 3-Mercapto-Analogen entstanden. Bei der Friedel-Crafts-katalysierten Silyl-Hilbert-Johnson Reaktion des Thiobenzoats8 in Verbindung mit den silylierten Nucleobasen Uracil, Thymin und N4-Isobutyrylcytosin9a–c entstanden nach der Schutzgruppenentfernung die 2′,3′-Didesoxy-3′-mercapto-Nucleoside11 und ihre Disulfide12. Unter ähnlichen Bedingungen ergaben die 2′,3′-Didesoxy-3′-methylthiopentofuranoside13 beide Anomere der 2′,3′-Didesoxy-3′-methylthionucleoside19 und20. Es wird das erste Beispiel einer direkten Kopplung 2,3-Didehydro-2,3-didesoxyfuranose vorgestellt. 2′,3′-Didesoxy-3′-mercaptocytidin zeigte Schutzwirkung gegenüber HIV-1 in MT-4 Zellen mit ED50=20 µM.
    Notes: Summary The iodide4(α) or7 synthesized in three steps from 2-deoxy-D-ribose1, has been subjected to a number of nucleophilic substitution reactions producing the 3-benzoylthio-, 3-methylthio- and the 3-thiocyanato-2,3-dideoxy-D-erythro-pentofuranosides8,13 and15, respectively, in addition to the disulfide17 of their 3-mercapto analogue. Subjecting the thiobenzoate8 to the Friedel-Crafts catalyzed silyl Hilbert Johnson reaction in conjunction with the silylated nucleobases of uracil, thymine and N4-isobutyrylcytosine9a–c resulted in the isolation of the 2′,3′-dideoxy-3′-mercapto nucleosides11 and their disulfides12 subsequent to deprotection. The 2,3-dideoxy-3-methylthio-pentofuranoside13 afforded both anomers of the 2′,3′-dideoxy-3′-methylthio nucleosides19 and20 under similar conditions. The first known example of a coupling directly on a 2,3-didehydro-2,3-dideoxyfuranose is presented. 2′,3′-Dideoxy-3′-mercaptocytidine showed protection against HIV-1 in MT-4 cells with ED50=20 µM.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Monatshefte für Chemie 122 (1991), S. 59-70 
    ISSN: 1434-4475
    Keywords: 2′,3′-Dideoxycytidines ; 2′,3′-Dideoxyuridines ; 5-Alkoxymethyluracils ; Human immunodeficiency virus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Ausgehend vonL-Glutaminsäure (1) wird eine modifizierte Synthese von geschützter 2,3-Dideoxyribose (5) beschrieben. Reaktion von5 mit silyliertem 5-Alkoxymethyluracilen7 b–e in Gegenwart von Trimethylsilyltriflat ergab anomere Mischungen der 2′,3′-Dideoxyuridinderivate8 a–e und9 a–e. Abspaltung der Schutzgruppe mit methanolischen Ammoniak und chromatographische Trennung ergab die entsprechenden Nucleoside10 a–e und11 a–e. Behandlung von9 b–e mit Tri(1H-1,2,4-triazol-1-yl)phosphinoxid und nachfolgende Reaktion von12 b–e mit Ammoniak in Dioxan ergab die Cytosinderivate13 b–e, welche nach Behandlung mit methanolischem Ammoniak die entsprechenden 2′,3′-Dideoxycytidinderivate14 b–e und15 b–e ergaben. Im Gegensatz zur Stammverbindung hatten diese Alkoxymethylderivate keine nennenswerte Wirksamkeit gegen den menschlichen Immunschwächevirus (HIV-1).
    Notes: Summary A modified synthesis of protected 2,3-dideoxyribose5 starting fromL-glutamic acid (1) is described. Reaction of5 with silylated 5-hydroxymethyluracil7 a and 5-alkoxymethyluracils7 b–e in the presence of trimethylsilyl triflate afforded an anomeric mixture of 2′,3′-dideoxyuridine derivatives8 a–e and9 a–e. Deprotection with methanolic ammonia and separation by chromatography gave the corresponding nucleosides10 a–e and11 a–e. Treatment of9 b–e with tri(1H-1,2,4-triazol-1-yl)phosphine oxide and subsequent reaction of12 b–e with ammonia in dioxane afforded the cytosine derivatives13 b–e which on treatment with methanolic ammonia gave the corresponding 2′,3′-dideoxycytidine derivatives14 b–e and15 b–e. In contrast with the parent compounds, these alkoxymethyl derivatives had no appreciable activity against human immunodeficiency virus (HIV-1).
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1432-0878
    Keywords: Pineal gland ; Astrocytes ; Glial fibrillary acidic protein (GFAP) ; Macrophages ; Microglia ; MHC class II antigen ; Rat (various stains)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Interstitial cells in the pineal gland of the rat were characterized immunocytochemically using the monoclonal antibodies MRC OX-42 and ED1 for macrophages/microglia, and MRC OX-6, which recognizes major histocompatibility complex (MHC) class II antigen. A polyclonal antibody against GFAP was used to identify astrocytes. Cells immunopositive for OX-42 and/or ED1 were distributed throughout the gland; they extended processes primarily along the perivascular spaces and occasionally within the parenchyma of the gland. Ultrastructurally, these OX-42-positive cells were characterized by a nucleus with sparse heterochromatin and cytoplasmic vacuoles/lysosomes. Cells expressing MHC class II antigen had a distribution and morphology similar to OX-42-immunopositive cells, suggesting that pineal macrophages/microglia play a role as antigen-presenting cells. GFAP-positive astrocytes were concentrated at the proximal end of the pineal where the pineal stalk enters the gland. The occurrence of antigenpresenting cells in the circumventricular neuroendocrine gland has important functional implications as these cells may be mediators of neuroimmunomodulatory mechanisms, and involved in certain disease states such as autoimmune pinealitis.
    Type of Medium: Electronic Resource
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