Modular Synthesis of 5-Substituted Thiophen-2-yl <i>C</i>-2′-Deoxyribonucleosides
作者:Jan Bárta、Radek Pohl、Blanka Klepetářová、Nikolaus P. Ernsting、Michal Hocek
DOI:10.1021/jo800177y
日期:2008.5.1
A new modular methodology of preparation of 5-substituted thiophene-2-yl C-nucleosides was developed. A Friedel−Crafts-type of C-glycosidation of 2-bromothiophene with toluoyl-protected methylglycoside 2 gave the desired protected 1β-(5-bromothiophen-2-yl)-1,2-dideoxyribofuranose 4a in 60%. The key intermediate 4a was then subjected to a series of palladium-catalyzed cross-coupling reactions. The cross-coupling