Two anomeric tricyclic nucleosides have been synthesised from diacetone-D-glucose using oxidation, stereoselective Grignard-addition of a vinyl-group, a stereoselective dihydroxylation followed by a tandem ring closing reaction, and finally a nucleobase coupling. The main beta-configured product was examined and its configuration confirmed using NMR-spectroscopy in connection to ab initio calculations. The preferred conformation of this tricyclic nucleoside was described.