Arabinoside benzyl

D-Glucose has been converted to 1-thio-D-glucitol derivatives, including mono- and di-sulphide dimers.Stannic chloride reduction of the arabinoside benzyl ether (21) yielded the glyceryl-heterocycle (22)(Scheme 8) the paper discusses the mechanism of the reaction involved in detail.Nitroheptenitol derivatives undergo... 

Toikka, M. Sipila, J. Teleman, A. Brunow, G. Lignin-carbohydrate model compounds. Formation of lignin-methyl arabinoside and lignin-methyl galactoside benzyl ethers via quinone methide intermediates. J. Chem. Soc., Perkin Trans. 1998, 1, 3813-3818. 

The data on reported cases of neurological disorders after intrathecal chemotherapy with methotrexate or cytosine arabinoside that could be attributed to benzyl alcohol or to other preservatives have been reviewed in the context of a case of flaccid paraplegia after intrathecal administration of cytosine arabinoside diluted in bacteriostatic water containing 1.5% benzyl alcohol (1). Most commonly, flaccid paraparesis, with absent reflexes, developed rapidly, often with pain and anesthesia. Very often there was full recovery. The prognosis depended mainly on the concentration of the preservative and on the time of exposure. In some cases, the paralysis ascended to cause respiratory distress, cardiac arrest, and death. Only preservative-free sterile CSF substitute or saline, or preferably the patient s own CSF, should be used to dilute chemotherapeutic agents (SEDA-11, 475). 

Illustrative of the fusion method, 6-methylthio-8-azapurine and 1-0-ace-tyl-2,3,5-tri-0-benzoyl-a-D-arabinofuranose, when fused at 200 C, gave the 7-, 8-, and 9-arabinosides in 5,24, and 37% yields, respectively. A similar reaction to make the ribofuranoside benefited from the catalytic action of bis-p-nitrophenyl phosphate. In an attempt to obtain the anomer, 6-methylthio-8-azapurine and 2,3,5-tri-O-benzyl- D-arabinofuranosyl chloride were fused (120 C, 45 min). Even under these mUder conditions, much anomerization to the unwanted a isomer occurred. In a modificaction of the fusion reaction, tetra-O-acetyl-D-ribofuranose was heated with 6-nonan-oylamino-8-azapurine to give azaadenosine in 14% yield. ... 

Conformational factors in furanoid sugars can dictate the stability of a frans-benzylthio-sulfonate system toward formation of episulfonium ion. Christensen and Goodman noted that the 3-)S-benzyl-3-thio-D-arabinoside ester (311) requires vigorous conditions for conversion into the mixture of azides (313) that arises by opening of the intermediate ion... 

Numerous syntheses have also been reported for arabinofuranosyl nucleoside analogues, prepared either conventionally from arabinofuranosyl derivatives or via 2,2-anhydro-nucleosides obtained from appropriate ribonucleosides. 5-Aza-cytosine-D-arabinoside has been synthesized and found to show similar antiviral activity to Ara-C(arabinosyl-cytosine). 7-a-, 7-<3-, 9-0 -, and 9- 3-arabino-furanosyl derivatives of 3-deazaguanine have also been prepared, but none showed any anti-tumour activity. 9-(o -D-Arabinofuranosyl)-8-aza[2- C]-adenine, 7-(/3-D-arabinofuranosyl)-pyrrolo[2,3-d]pyrimidine-4(3//)-one (15)," l-(a-D-arabinofuranosyl)- and l-(/3-D-xylofuranosyl)-4-nitropyrazole, and Ot-arabino-nucleosides of 5-fluoro-cytosine and -uracil derivatives have also been prepared. An improved synthesis of 9-(/3-D-arabinofuranosyl)-2-fluoro-adenine has been reported. The ratio of o to 3 anomers obtained by phase-transfer reaction of 2,3,5-tri-O-benzyl-D-arabinofuranosyl bromide with 6-chloro-2-thiomethyl-7-deazapurine varied with the quaternary ammonium salt used as a catalyst, although the jU-anomer predominated in every case. 2,2-Anhydro-nucleosides have been used to prepare l-j3-D-arabinofiiranosyl derivatives of 5-alkylthio-uracils, 5-ethyl-cytosine, and 5-ethyl-uracil, 8-alkylamino-purines, and 2-aralkylamino-l,4-dihydro-4-imino-pyrimidine hydrochlorides (16). ... 

CB tribenzyl-D-arabinofuranoside 59 was efficiently prepared from methyl tribenzyl-D-arabinofuranoside 57 as shown in Scheme 3. Treatment of 57 with acetyl bromide in trifluoroacetic acid and subsequent coupling of the resulting crude arabinofuranosyl bromide with benzyl 2-(hydroxymeAyl)benzoate (1) followed by selective hydrogenoiysis of the resulting BCB arabinofuranoside 58 (a/p=4 l) afforded the desired CB arabinoside 59. CB 3,5-di-(9-benzoyl-2-0-benzylarabinofuranoside 60 was also prepared in like fashion. 

A high yield of 1,4-jS-linked product was obtained when methyl 2,3-anhydro-j3-D-ribopyranoside was condensed with 3,4-di-0-acetyl-2-0-benzyl-a-D-xylopyranosyl bromide, and use of tri-O-acetyl-a-D-xylopyranosyl bromide afforded the related product which, on base-catalysed hydrolysis, gave the methyl jS-xylobioside. Several 2-0-glycosyl-D-arabinoses have been prepared by glycosylation of benzyl 3,4-0-isopropylidene-j8-D-arabinopyranoside, and from benzyl 2-0-j3-D-glucopyranosyl-jS-D-arabinoside the aldobiuronic acid was produced. ... 

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