Regioselective lipase-catalyzed (Novozym 435(R) from Candida antartica) acylations of unprotected 2-deoxy-D-ribose and D-ribose, by use of propionic anhydride, afforded the novel 5-O-monoacylated derivatives 1 and 4, respectively. Subsequent addition of acetic anhydride and pyridine into the reaction mixtures gave the corresponding per-O-acylated pentofuranoses 2 and 5 in almost quantitative overall yields from the unprotected carbohydrates. The versatility of compound 2 as an universal synthon for synthesis of anomeric mixtures of 2'-deoxynucleosides is demonstrated.