Vertical decorative line
Research Center for Complex Molecular Systems and Biomolecules
Center for Biomolecules and Complex Molecular Systems   
Supported by the Ministry of Education, Czech Republic      
Decorative element
Decorative element
Decorative element Research | Papers | People | Events | Archive | Teach | Contact   
Decorative element
Empty gif
Empty space gif.
Abstract of the article
Empty gif Empty gif
New modular and efficient approach to 6-substituted pyridin-2-yl C-nucleosides.

Urban, M.; Pohl, R. ; Klepetarova, B. etc., Journal of Organic Chemistry, 71 [19] 7322 - 7328 (2006)

A novel modular, efficient, and practical methodology of preparation of 6-substituted pyridin-2-yl C-nucleosides was developed. An addition of 2-lithio-6-bromopyridine 2b to TBDMS-protected 2-deoxyribonolactone 5 gave aduct 7 as an equilibrium mixture of anomeric hemiketals 1-(6-bromopyridin-2-yl)-1-hydroxynucleosides 7a, b and its open form 7c. Reduction of the adduct 7 with Et3SiH and BF3 center dot Et2O afforded the desired 6-bromonucleoside 8a as pure beta-anomer in a total yield of 32% over two steps from 5. Intermediate 8a was then subjected to a series of palladium catalyzed cross-coupling reactions and aminations to give a series of protected 1 beta-(6-alkyl-, 6-aryl-, and 6-aminopyridin-2-yl)-2-deoxyribonucleosides 9. Catalytic hydrogenation of 8a gave an unsubstituted pyridine C-nucleoside, and diazotative oxodeamination of 6-aminopyridine nucleoside 9f by isopentyl nitrite in acetic acid gave 6-oxopyridine nucleoside 10i. Deprotection of silylated nucleosides 9 by Et3N center dot 3HF gave a series of free C-nucleosides 10.


<< Go back
Empty space gif.
Empty gif
Decorative element