Abstract D-Eritadenine (Ia) and L-eritadenine (IIa) were prepared from 5-(adenin-9-yl)-5- deoxyaldofuranoses or enantiomeric 2, 3-disubstituted erythronolactones (VIIIb, c, XIV). Oxidation of methyl 2, 3-O-isopropylidene-D-ribofuranoside (IX) with periodate in the presence of ruthenium, followed by acid hydrolysis and reduction with sodium borohydride, afforded L-ribonolactone (XI). Its 2, 3-O-isopropylidene derivative was subjected to ...