- Isonucleosides: Design and synthesis of new isomeric nucleosides with antiviral potential
-
Isonucleosides discovered in our laboratory have been found to have interesting antiviral activity. The design, development of methodology, and stereochemical synthesis of new isonucleosides of anti-HCV interest are described. Antiviral results are cited.
- Nair, Vasu,Piotrowska, Dorota G.,Okello, Maurice,Vadakkan, Jean
-
-
Read Online
- Syntheses and complexing ability of α-d-gluco- and α-d-xylofuranoside-based lariat ethers
-
Chiral monoaza-15-crown-5 lariat ethers attached to a 1,2-O-isopropylidene-α-d-glucofuranoside unit (10–13), monoaza-16-crown-5 lariat ethers fused to 1,2-O-isopropylidene-α-d-glucofuranoside- (18) and to 1,2-O-isopropylidene-α-d-xylofuranoside units (23 and 24) have been synthesized. The alkali metal- and ammonium picrate extracting ability of these macrocycles was investigated in dichloromethane–water system. In general, the 15-membered macrocycles (10–13) showed, for almost all cations, a more considerable extracting ability, than the 16-membered lariat ethers (18, 23 and 24). Plasticized PVC membrane electrodes (ISEs) were prepared from the α-d-glucofuranoside-based triphenylmetyl (trityl) ether derivative (18), and its potentiometric selectivities and complex formation constants were determined with the segmented sandwich membrane method. Furthermore, the binding affinities of ionophores to different metal ions were also measured by competitive ESI–MS experiments. One of the 1,2-O-isopropylidene-α-d-glucofuranoside-based lariat ethers (13) exhibited a high selectivity for silver ion (Ag+).
- Rapi, Zsolt,Ozohanics, Oliver,Tóth, Gábor,Bakó, Péter,H?fler, Lajos,Nemcsok, Tamás,Kánya, Nándor,Keglevich, Gy?rgy
-
-
- Novel selectivity in carbohydrate reactions, IV: DABCO-mediated regioselective primary hydroxyl protection of carbohydrates
-
An efficient procedure for the regioselective tritylation of primary hydroxyl group of aldohexopyranosides and nucleosides using trityl chloride in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) in dichloromethane has been developed. Subsequent acetylation of the tritylated products in the same pot has been made possible, thereby providing an efficient route to the fully protected carbohydrate derivatives that can be discriminated chemoselectively.
- Gadakh, Bharat Kacheshwar,Patil, Premanand Ramrao,Malik, Satish,Kartha, K. P. Ravindranathan
-
experimental part
p. 2430 - 2438
(2009/12/03)
-
- Temperature dependence of the distribution of trityl groups in the tritylation of 1,2-O-isopropylidene-α-D-glucofuranose
-
The tritylation reaction of 1,2-O-isopropylidene-α-D-glucofuranose with 2.4 molar amounts of trityl chloride in pyridine at 70 °C for 20 h gave the 5,6-di-O-trityl derivative in 50% yield as the major product, whereas the reaction at 115 °C mainly gave the 3,6-di-O-trityl derivative (26% yield) along with the 6-O-trityl derivative (48% yield). The fact that the yield of the 5,6-di-O-trityl derivative at 115 °C decreased after 1 h and was 12% at 20 h is due to the redistribution of trityl groups including detritylation assisted by pyridinium chloride. It was found that tritylation of the primary hydroxyl group at C-6 was almost completed within 10 min at 115 °C.
- Morishima, Naohiko,Mori, Yoko
-
p. 1481 - 1483
(2007/10/03)
-
- Stereospecific synthesis of (+)-muscarine from D-glucose, suitable for preparation of 5-substituted analogues
-
A stereospecific synthesis of (+)-muscarine iodide (1) has been achieved starting from D-glucose as a chiral precursor. The key steps of the synthesis involved a stereospecific cyclization of 3,5-di-O-mesyl derivative 3 into the 2,5-anhydride 4, the stereospecific catalytic hydrogenation of unsaturated derivative 6, and the C-4 epimerization of alcohol 12 by Mitsunobu reaction.
- Popsavin, Velimir,Beric, Ostoja,Radic, Ljubica,Popsavin, Mirjana,Cirin-Novta, Vera,Miljkovic, Dusan
-
p. 1522 - 1527
(2007/10/03)
-
- Virtual 1H-1H spin-spin coupling in a linear five-spin system on the pyranose rings of some glucuronides
-
In the 1H NMR spectra of methyl 2,3,4-tri-O-acetyl-β-D-glucopyranosyluronate-(1 -> 3)-1,2:5,6-di-O-isopropylidene-α-D-glucofuranose (6) and methyl 2,3,4-tri-O-acetyl-β-D-glucopyranosyluronate-(1 -> 6)-1,2:3,5-di-O-isopropylidene-α-D-glucofuranose (7), which were obtained by the reaction of 1,2;5,6-di-O-isopropylidene-α-D-glucofuranose (1) with methyl 2,3,4-tri-O-acetyl-α-D-glucopyranosyluronate bromide (5) in the presence of Hg(CN)2 in 1:1 benzene-nitromethane at 45 deg C, protons on both β-D-glucopyranosyluronate rings were observed as very complex signals that could not be interpreted by first-order analysis.Similar complex signals were also observed for the protons on the β-D-glucopyranosyluronate rings that were sugar components of some triterpenoidal glycosides (13-15).These complex signals were determined to be due to virtual long-range spin-spin coupling in the linear five-spin system on the glucopyranosyluronate rings of the glucuronides by 1H, 13C, H-C COSY, 1D HOHAHA, and spin-simulation spectroscopies.
- Saito, Setsuo,Sasaki, Yuka,Furumoto, Takako,Sumita, Shigeya,Hinomoto, Tohru
-
-
- Synthesis of Methyl 2,6-di-O-methyl-α-D-glucofuranoside
-
Methyl 2,6-di-O-methyl-α-D-glucofuranoside has been prepared from 1,2-O-isopropylidene-α-D-glucofuranose in five convenient steps in a good yield.
- Mukherjee, Atreyee,Roy, Nirmolendu
-
p. 1037 - 1038
(2007/10/02)
-