A new stereo- and regioselective synthesis for adenosine analogous nucleosides is described. Starting from 2- and 6-substituted 4-amino-7(8H)-pteridinones, DBU deprotonation and the ribosylation with an α-haloribofuranose derivative leads to the corresponding pteridine-N-8-β-D-nucleosides in reasonably good yields1.