- CYCLIC DINUCLEOTIDES AS ANTICANCER AGENTS
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The present invention is directed to compounds of the formulae I, II and III as shown below wherein all substituents are defined herein, as well as pharmaceutically acceptable compositions comprising compounds of the invention and methods of using said compositions in the treatment of various disorders.
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Paragraph 1450; 1451; 1452
(2019/02/13)
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- Preparation of high-octane oxygenate fuel components from plant-derived polyols
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The ketalization of polyols (glycerol, xylitol, xylose) in the presence of a number of heterogeneous acid catalysts has been studied. It has been shown that zeolite catalysts exhibit high activity in the formation of the acetone ketal of glucose in a flow system with the quantitative selectivity for the 1,2-product. The best catalyst is zeolite β in the presence of this zeolite and excess acetone, the yield is over 90% or, in the case of the structured reactor, even greater than 98% It has been shown that zeolite-based systems catalyze the formation of ketals of xylitol and xylose with a yield of up to 50% in the presence of excess acetone.
- Maksimov,Nekhaev,Ramazanov,Arinicheva,Dzyubenko,Khadzhiev
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experimental part
p. 61 - 69
(2011/10/08)
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- 1,2-Cyclic sulfite and sulfate furanoside diesters: improved syntheses and stability
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The facile syntheses of 1,2- and 3,5-cyclic sulfite and sulfate furanoside diesters were conducted in molecular solvents and ionic liquids in the presence of immobilised morpholine. Molecular solvents and ionic liquids performed similarly with regards to overall yields. However, the use of ILs allowed for the reactions to be carried out under atmospheric conditions and showed good recyclability. Additionally, increases in product stability was achieved in ILs over organic solvents, in particular, in bis{(trifluoromethanesulfonyl)imide} and trispentafluoro-ethyltrifluorophosphate-based ionic liquids, which were also excellent media to control the hydrolysis of thionyl chloride and sulfuryl chloride.
- Hardacre, Christopher,Messina, Ivano,Migaud, Marie E.,Ness, Kerry A.,Norman, Sarah E.
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experimental part
p. 6341 - 6347
(2009/12/04)
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- Process for the preparation and separation of arabinose and xylose from a mixture of saccharides
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A process for the preparation and separation of the pentoses, xylose and arabinose from mixtures of saccharides by forming acetals is described. D-xylose is a precursor to xylitol, a sweetener, and L-arabinose is a precursor to the drug intermediate (R)-3,4-dihydroxybutyric acid, carnitine and agrichemicals.
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Page/Page column 3
(2008/06/13)
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- An economic synthesis of 1,2,3,4-tetra-O-acetyl-5-thio-D-xylopyranose and its transformation into 4-substituted-phenyl 1,5-dithio-D-xylopyranosides possessing antithrombotic activity
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D-Xylose was converted via 1,2-O-isopropylidene-α-D-xylofuranose (4) into 3-O-benzoyl-5-S-benzoyl- 1,2-O-isopropylidene-α-D-xylofuranose which, after methanolysis, acetylation and subsequent acetolysis afforded 1,2,3,4-tetra-O-acetyl-5-thio-α-D-xylopyranose (14) in an overall yield of 36%. Reaction of 4 with thionyl chloride gave a mixture of the diastereomeric cyclic sulfites, the structures of which were established by X-ray crystallography. Their oxidation with sodium periodate afforded the corresponding cyclic sulfate 23. Treatment of 23 with potassium thioacetate gave the potassium salt of 5-S-acetyl-1,2-O-isopropylidene-α-D-xylofuranose 3-O-sulfonic acid (26) which, after methanolysis, acetylation and subsequent acetolysis afforded 14 in an overall yield of 56%. Treatment of 4 with sulfuryl chloride gave a mixture containing 5-chloro-3-O-chlorosulfonyl-5-deoxy-1, 2-O-isopropylidene-α-D-xylofuranose, 3,7,9,11-tetraoxa-4-thia-10-dimethyl-tricyclo[6,3,0,02,6]undecane S-dioxide and 23 in a 2:3:7 ratio. Tetraacetate 14 was converted into the α-1-bromide 18 as well as into the α-1-O-trichloroacetimidate 17. These three compounds were used as donors for the glycosylation with 4-cyanothiophenol, affording the 4-cyanophenyl 2,3,4-tri-O-acctyl-1,5-dithio-α- (29) and β-D-xylopyranoside (30) in different ratios, depending on the reaction conditions, When donor 18 was used in the presence of potassium carbonate, besides 29 and 30 two aryl C-glycosylated-thioglycosides, i.e. 4-cyano-2-(2, 3,4-tri-O-acetyl-5-thio-β-D- xylopyranosyl)phenyl 2,3,4-tri-O-acetpy-1,5-dithio-α- and β-D-xylopyranoside (32 and 33) as well as 4-cyano-2-(2,3,4-tri-O-acetyl-5-thio-β-D-xylopyranosyl)phenyl disulfide 34 could be isolated as byproducts. Deacetylation of 30 with sodium methoxide in methanol afforded, besides 4-cyanophenyl 1,5-dithio-β-D-xylopyranoside (1), the corresponding 4-[(methoxy)(imino)methyl]phenyl glycoside 2. The 4-cyano group of 1 was converted into the 4-aminothiocarbonyl, the 4-(methylthio)(imino)methyl, the 4-amidino and the 4-(imino)(hydrazino)methyl group. All of these glycosides showed a significant antithrombotic activity on rats.
- Bozo, Eva,Boros, Sandor,Kuszmann, Janos,Gacs-Baitz, Eszter,Parkanyi, Laszlo
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p. 297 - 310
(2007/10/03)
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- Synthesis of 3'-amino-3'-deoxyadenosine derivatives as potential drugs for the treatment of malaria
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A series of 3'-substituted 3'-amino-3'-deoxyadenosine analogues were synthesized and subsequently tested against the human malaria parasite Plasmodium falciparum in vitro. Several amongst them displayed pronounced antiplasmodial activities.
- Soenens,Francois,Van den Eeckhout,Herdewijn
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p. 409 - 411
(2007/10/02)
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- One-pot synthesis of 1,2-O-isopropylidene-α-D-xylofuranose
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The title compound 1 was prepared by sulfuric acid-catalyzed acetalation of D-xylose followed by partial hydrolysis with aqueous sodium carbonate added directly to a crude acetalation mixture.The yield of crystalline 1 (mp 42-43 deg C) was 80percent. Keywords: 1,2-O-Isopropylidene-α-D-xylofuranose; 1,2:3,5-di-O-Isopropylidene-α-D-xylofuranose; Acetalation; D-Xylose; Partial hydrolysis
- Moravcova, Jitka,Capkova, Jindra,Stanek, Jan
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- Nucleosides. LVI. Synthesis and chemical modifications of 3'-deoxy- pyrimidine nucleosides
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3'-Deoxyuridine(1) and 3'-deoxycytidine(2) were prepared with improved yields by two different methods applying either the Barton procedure to appropriate 2',5'-di-O-protected pyrimidine nucleosides or by choosing the direct glycosylation of the pyrimidine bases with 1,2-di-O-acetyl-5-O- toluoyl-3-deoxy-D-erythro-pentofuranose via the silylation approach. Suitable protecting groups for the sugar moiety have been found in the trityl, tert- butyldimethylsilyl and the thexyl groups which are inert in the radical deoxygenation process. The newly synthesised compounds were characterized by elemental analyses and UV and 1H-NMR spectra.
- Rhie,Pfleiderer
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p. 1425 - 1452
(2007/10/02)
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- IODINE, A NOVEL CATALYST IN CARBOHYDRATE REACTIONS. I. O-ISOPROPYLIDINATION OF CARBOHYDRATES
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Iodine is found to serve as an excellent catalyst in the O-isopropylidination of sugars and sugar alcohols.
- Kartha, K.P.R.
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p. 3415 - 3416
(2007/10/02)
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