Synthesis of Deoxy, Dideoxy and Didehydrodideoxy Analogs of 9-(4-C-Hydroxymethyl-α-L-pentofuranosyl)adenine

1994 ◽  
Vol 59 (7) ◽  
pp. 1654-1664 ◽  
Author(s):  
Hubert Hřebabecký ◽  
Antonín Holý
Keyword(s):  
Antiviral Activity ◽  
Catalytic Hydrogenation ◽  
Sodium Methoxide ◽  
Reductive Elimination ◽  
Bromo Derivative ◽  
Epoxy Derivative ◽  
Subsequent Deacetylation ◽  
Tin Tetrachloride

Condensation of 1,2-di-O-acetyl-3,5-di-O-benzoyl-4-C-benzoyloxymethyl-L-arabinofuranose with N6-benzoyladenine, catalyzed with tin tetrachloride, afforded nucleoside I, which upon partial deacetylation and subsequent mesylation was converted into 9-(3,5-di-O-benzoyl-4-C-benzoyloxymethyl-2-O-methanesulfonyl-α-L-arabinofuranosyl)adenine (III). 9-(2,5,6-Tri-O-acetyl-4-C-acetoxymethyl-3-O-methanesulfonyl-α-L-arabinofuranosyl)-N6-benzoyladenine (V) was obtained by condensation of 1,2,5-tri-O-acetyl-4-C-acetoxymethyl-3-O-methanesulfonyl-L-arabinose with N6-benzoyladenine. Reaction of mesyl derivatives III and V with methanolic sodium methoxide afforded 2',3'-anhydro nucleosides VIa and VIIa, which were acetylated to give 9-(5-O-acetyl-4-C-acetoxymethyl-2,3-anhydro-α-L-ribofuranosyl)adenine (VIb) and 9-(5-O-acetyl-4-C-acetoxymethyl-2,3-anhydro-α-L-lyxofuranosyl)adenine (VIIb). Epoxy derivative VIb was cleaved with bromotrimethylsilane to 9-(5-O-acetyl-4-C-acetoxymethyl-2-bromo-2-deoxy-α-L-arabinofuranosyl)adenine (VIIIa); the same reaction with epoxy derivative VIIb afforded a mixture of 9-(5-O-acetyl-4-C-acetoxymethyl- 2-bromo-2-deoxy-α-L-xylofuranosyl)adenine (IXa) and 9-(5-O-acetyl-4-C-acetoxymethyl-3-bromo- 3-deoxy-α-L-arabinofuranosyl)adenine (Xa). Their dehalogenation with tributylstannane and subsequent deacetylation led to 9-(2-deoxy-4-C-hydroxymethyl-α-L-erythro-pentofuranosyl)adenine (VIIIc), 9-(2-deoxy-4-C-hydroxymethyl- α-L-threo-pentofuranosyl)adenine (IXc) and 9-(3-deoxy-4-C-hydroxymethyl-α-L-threo-pentofuranosyl)adenine (Xc). 9-(2,5-Di-O-acetyl-4-C-acetoxymethyl-2-bromo-2-deoxy-α-L-arabinofuranosyl)adenine (VIIId), prepared by acetylation of VIIIa, on reductive elimination with Cu/Zn couple and subsequent deacetylation afforded 9-(2,3-dideoxy-4-C-hydroxymethyl-α-L-glycero-pent-2-enofuranosyl)adenine (XIb). 9-(2,3-Dideoxy-4-C-hydroxymethyl-α-L-glycero-pentofuranosyl)adenine (XIIb) was obtained either by catalytic hydrogenation of bromo derivative VIIId, followed by deacetylation, or by catalytic hydrogenation of didehydro derivative XIb. The nucleosides synthesized were tested for antiviral activity.

Synthesis of Deoxy, Dideoxy and Didehydrodideoxy Analogs of 9-(β-D-Hexofuranosyl)adenine

1994 ◽  
Vol 59 (6) ◽  
pp. 1408-1419 ◽  
Author(s):  
Hubert Hřebabecký ◽  
Jan Dočkal ◽  
Antonín Holý
Keyword(s):  
Antiviral Activity ◽  
Catalytic Hydrogenation ◽  
Sodium Methoxide ◽  
Reductive Elimination ◽  
Bromo Derivative ◽  
Epoxy Derivative ◽  
Subsequent Deacetylation ◽  
Methanolic Ammonia ◽  
Tin Tetrachloride

Condensation of 1,2-di-O-acetyl-3,5,6-tri-O-benzoyl-D-glucofuranose with N6-benzoyladenine, catalyzed with tin tetrachloride, afforded nucleoside I. Partial deacetylation of I, followed by mesylation, gave 9-(3,5,6-tri-O-benzoyl-2-O-methanesulfonyl-β-D-glucofuranosyl)adenine (III). 9-(2,5,6-Tri-O-acetyl-3-O-methanesulfonyl-β-D-glucofuranosyl)-N6-benzoyladenine (IV) was prepared by condensation of 1,2,5,6-tetra-O-acetyl-3-O-methanesulfonyl-D-glucofuranose with N6-benzoyladenine. Reaction of mesyl derivative III with methanolic sodium methoxide and of mesyl derivative IV with methanolic ammonia led to 2',3'-anhydronucleosides V and VI which were acetylated to give the respective 9-(5,6-di-O-acetyl-2,3-anhydro-β-D-mannofuranosyl)adenine (VII) and 9-(5,6-di-O-acetyl-2,3-anhydro-β-D-allofuranosyl)adenine (VIII). Epoxy derivative VII was cleaved with bromotrimethylsilane, affording a mixture of 9-(5,6-di-O-acetyl-2-bromo-2-deoxy-β-D-glucofuranosyl)adenine (Xa) and 9-(5,6-di-O-acetyl-3-bromo-3-deoxy-β-D-altrofuranosyl)adenine (XIa), epoxy derivative VIII was cleaved analogously to give 9-(5,6-di-O-acetyl-3-bromo-3-deoxy-β-D-glucofuranosyl)adenine (XIIa). Their dehalogenation with tributylstannane and subsequent deacetylation led to 9-(2-deoxy-β-D-arabino-hexofuranosyl)adenine (Xc), 9-(3-deoxy-β-D-arabino-hexofuranosyl)adenine (XIc) and 9-(3-deoxy-β-D-ribo-hexofuranosyl)adenine (XIIc). 9-(2,5,6-Tri-O-acetyl-3-bromo-3-deoxy-β-D-glucofuranosyl)adenine (XIId), which was prepared by acetylation of XIIa, on reductive elimination with Cu/Zn couple and subsequent deacetylation gave 9-(2,3-dideoxy-β-D-erythro-hex-2-enofuranosyl)adenine (XIV). 9-(2,3-Dideoxy-β-D-erythro-hexofuranosyl)adenine (XVI) was obtained either by catalytic hydrogenation of bromo derivative XIId followed by deacetylation, or by catalytic hydrogenation of didehydro derivative XIV. The synthesized nucleosides were tested for antiviral activity.

Über 5-Hydroxymethyl-cytidin und 5-Hydroxymethyl-cytosin-N-3-β-D-glucopyranosid sowie über reaktionsfähige Vorstufen

1966 ◽  
Vol 21 (10) ◽  
pp. 942-952 ◽  
Author(s):  
Reinhard Brossmer ◽  
Erich Röhm
Keyword(s):  
Hydrochloric Acid ◽  
Benzyl Alcohol ◽  
Catalytic Hydrogenation ◽  
Sodium Methoxide ◽  
Room Temperature ◽  
Selective Removal ◽  
Protecting Groups ◽  
Hydroxymethyl Cytosine ◽  
Analogous Manner ◽  
Synthetic Intermediates

5-Benzyloxymethyl-NNH2-benzoyl-cytosine (4) is formed from 5-hydroxymethyl-cytosine (1) in 80% yield by benzylation and subsequent benzoylation. The benzylation readily takes place with benzyl alcohol and catalytic amounts of hydrochloric acid in tetrahydrothiophen-1.1-dioxide as solvent. — 4 is quantitatively converted in pyridine at room temperature to a toluene soluble mercury (II) salt 5.5 condenses easily with 2.3.5-tribenzoyl-D-ribofuranosyl chloride to give the β-nucleoside 6, no a-anomer being found. — The removal of all protecting groups by catalytic hydrogenation and treatment with sodium methoxide or ammonia leads to cristalline 5-hydroxymethyl cytidine 10 (ca. 60% yields based on 1). — In an analogous manner N-3-β-D-glucosyl-5-hydroxymethyl-cytosine 15 is prepared. — Selective removal of certain of the protecting groups in 6 and 11 yields potentially valuable synthetic intermediates.

Cyclizations of dialdehydes with nitromethane. XIV. The isolation of four crystalline methyl 3,6-dideoxy-3-nitro-α-L-hexopyranosides

1969 ◽  
Vol 47 (1) ◽  
pp. 99-103 ◽  
Author(s):  
Hans H. Baer ◽  
Karel Čapek
Keyword(s):  
Reaction Time ◽  
Catalytic Hydrogenation ◽  
Chromatographic Separation ◽  
Sodium Methoxide ◽  
Room Temperature ◽  
Total Yield

Cyclization of L′-methoxy-L-methyldiglycolic aldehyde (1) with nitromethane and sodium methoxide in methanol (40 min at room temperature) furnished four crystalline methyl 3,6-dideoxy-3-nitro-α-L-hexopyranosides in a combined yield of 75%. Chromatographic separation gave the gluco (2), manno (3), talo (4), and galacto (5) isomers in an approximate ratio of 18:8:3:1. Shortening of the reaction time to 25 min decreased the total yield to 53% at the expense of 2, the ratio of isolated products being 8:8:2.3:1.7. The configurations of the new nitro glycosides 3, 4, and 5 were proven by catalytic hydrogenation followed by N-acetylation, which gave the known 3-acetamido derivatives.

Mechanistic insights into hydride transfer for catalytic hydrogenation of CO2 with cobalt complexes

2014 ◽  
Vol 43 (31) ◽  
pp. 11803-11806 ◽  
Author(s):  
N. Kumar ◽  
D. M. Camaioni ◽  
M. Dupuis ◽  
S. Raugei ◽  
A. M. Appel
Keyword(s):  
Catalytic Hydrogenation ◽  
Hydride Transfer ◽  
Cobalt Complexes ◽  
Reductive Elimination ◽  
Hydrogenation Of Co2 ◽  
Hydrogenation Of Co

The catalytic hydrogenation of CO2 to formate by Co(dmpe)2H can proceed via direct hydride transfer or via CO2 coordination to Co followed by reductive elimination of formate.

Branched-chain aminodeoxy sugars. Methyl 3-C-aminomethyl-2-deoxy-α-D-ribo-hexopyranoside and methyl 3-C-aminomethyl-2-deoxy-α-D-arabino hexopyranoside

1970 ◽  
Vol 48 (19) ◽  
pp. 3034-3038 ◽  
Author(s):  
Alex Rosenthal ◽  
Khong-Seng Ong
Keyword(s):  
Catalytic Hydrogenation ◽  
Sodium Methoxide ◽  
Acetyl Derivative ◽  
Molar Equivalent ◽  
Branched Chain

Addition of methyl 4,6-O-benzylidene-2-deoxy-α-D-erythro-hexopyranosid-3-ulose (1) to excess nitromethane and 1 molar equivalent of sodium methoxide in methanol gave methyl 4,6-O-benzylidene-2-deoxy-3-C-nitromethyl-α-D-ribo-hexopyranoside (2) and the arabino stereoisomer 3 in 63 and 22% yields, respectively. The proof of structure of the branched-chain deoxy nitro sugars is described. Debenzylidenation of the nitro sugars afforded the partially blocked nitro sugars 4 and 5. Catalytic hydrogenation of the latter or of 2 and 3 yielded the branched-chain aminodeoxy sugars 7 and 9 (7 characterized as its N-acetyl derivative and 9 as its N-2,4-dinitrophenyl derivative).

Immunocytochemical localization of desmin and vimentin in chick embryonic myocardial cells

1990 ◽  
Vol 48 (3) ◽  
pp. 448-449
Author(s):  
Yukiko Sugi
Keyword(s):  
Sodium Methoxide ◽  
Intermediate Filament Protein ◽  
Chick Embryos ◽  
Immunocytochemical Localization ◽  
Myocardial Cells ◽  
Immunofluorescence Study ◽  
Immunofluorescent Localization ◽  
Rabbit Igg ◽  
Semithin Sections ◽  
Filament Protein

In cultured skeletal muscle cells of chick, one intermediate filament protein, vimentin, is primarily formed and then synthesis of desmin follows. Coexistence of vimentin and desmin has been immunocytochemically confirmed in chick embryonic skeletal musclecells. Immunofluorescent localization of vimentin and desmin has been described in developing myocardial cells of hamster. However, initial localization of desmin and vimentin in early embryonic heart has not been reported in detail. By quick-freeze deep-etch method a loose network of intermediate filaments was revealed to exist surrounding myofibrils. In this report, immunocytochemical localization of desmin and vimentin is visualized in early stages of chick embryonic my ocardium.Chick embryos, Hamburger-Hamilton (H-H) stage 8 to hatch, and 1 day old postnatal chicks were used in this study. For immunofluorescence study, each embryo was fixed with 4% paraformaldehyde and embedded in Epon 812. De-epoxinized with sodium methoxide, semithin sections were stained with primary antibodies (rabbit anti-desmin antibody and anti-vimentin antibody)and secondary antibody (RITC conjugated goat-anti rabbit IgG).

Antiviral activity of EPs® 7630 as assessed in a fibroblast-virus protection assay

Planta Medica ◽  
2009 ◽  
Vol 75 (09) ◽  
Author(s):  
C Thaele ◽  
A Janecki ◽  
AF Kiderlen ◽  
H Kolodziej
Keyword(s):  
Antiviral Activity ◽  
Protection Assay
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