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[reaction: see text] An efficient route to all of the possible cross-linked 2'-deoxypurines 1-3 has been developed by means of the Pd-mediated C-N bond formation in the key step. Utilizing this protocol, the synthesis of the first unnatural protected purine trimeric adduct 4 has been accomplished. 相似文献
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A straightforward access to protected 8-fluoro nucleosides via metalation-electrophilic fluorination under heterogeneous reaction conditions is reported. This is the first synthesis of 8-fluoro-2'-deoxyribonucleoside derivatives. Phenylsulfonyl substituted nucleosides are accompanying byproducts, possibly indicating a competing radical process. Higher yields of 8-fluoro derivatives were obtained with 2'-deoxyribonucleosides, as compared to ribonucleosides. Deprotection of the hydroxyl groups leading to 8-fluoro-2'-deoxyadenosine using TASF in methylene chloride demonstrates the compatibility of desilylation with 8-fluoro substituted nucleosides. NMR data indicate a syn conformation of the 8-fluoro derivatives. 相似文献
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The preparation of glucosyl and ribosyl derivatives of 3,4,5-triamino-2H-1,2,6-thiadiazine 1,1-dioxide ( 2 ), 7-amino-4H-furazano[3,4-c]- and 7-amino-1H, 4H-imidazo[2,3-c][1,2,6]thiadiazine 5,5-dioxide ( 3 and 4 respectively) is described. Different synthetic approaches have been used. 相似文献
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Hanessian S Huang G Chenel C Machaalani R Loiseleur O 《The Journal of organic chemistry》2005,70(17):6721-6734
Methods are described for the total synthesis of bicyclic perhydrofuropyran nucleosides as N-analogues of the naturally occurring malayamycin A. Formation of the N-nucleosides relied on the activation of thioglycosides, proceeding via sulfonium intermediates. Ring closure metathesis was used in two approaches to build the bicyclic dioxa heterocycle. Another approach relied on the use of a sugar precursor and cyclization to the bicyclic thioglycoside. 相似文献
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There are reports in the literature that placement of an arylamino side chain at the C-2 position of purine nucleosides produces compounds capable of inhibiting DNA polymerase. To evaluate the potential of this class of compounds as antiviral agents that act by inhibiting viral DNA polymerase, ara-carbocyclic purine nucleosides possessing a 4-(l-butyl)phenylamino and a 3,5-dichlorophenylamino substituent at C-2 were chosen as the prototype structures and have been prepared from 2,4,6-trichloropyrimidine in 6 steps. For the antiviral analysis, human cytomegalovirus served as the principal virus since it expresses a virally specific DNA polymerase. None of the compounds showed activity towards this virus, but they were found to display some toxicity towards one or more cell lines. 相似文献
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S. A. Giller A. Khettskhaim T. I. Krukle I. A. Drizina 《Chemistry of Heterocyclic Compounds》1976,12(4):461-464
A number of 6-substituted 9-(1,5-dihydroxy-3-pentyl)purines were obtained from 5-amino-4,6-dichloropyrimidine. 5-Amino-4,6-dichloropyrimidine reacts with 2-hydroxymethylpyrrolidine to give 4-chloro-5-amino-6-(2-hydroxymethylpyrrolidino)pyrimidine.See [1] for communication IV.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 552–555, April, 1976. 相似文献
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S. A. Giller† A. Khettskhaim I. A. Drizina T. M. Krukle 《Chemistry of Heterocyclic Compounds》1976,12(5):582-586
Phosphorylation of 6-substituted 9-(1, 5-dihydroxy-3-pentyl)purines with 2-cyanoethyl phosphate in the presence of dicyclohexylcarbodiimide in anhydrous pyridine gave their 1, 5-diphosphates. Oligomers containing pyrophosphate and ester bonds were obtained by polycondensation of 1, 5-diphosphates of 6-dimethylamino- and 6-oxo-9-(1, 5-dihydroxy-3-pentyl)purines with the appropriate 9-(1, 5-dihydroxy-3-pentyl) purines.See [1] for communication V.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 693–696, May, 1976. 相似文献