Stereoselective synthesis of azanucleosides aza-stavudine (aza-D4T), aza-2′,3′-didehydro-3′-deoxyuridine (aza-D4U), and its hydrogenated analogues from an endocyclic enecarbamate

The stereoselective synthesis of the aza-analogues of nucleosides stavudine (D4T) and dideoxyuridine (DDU) were accomplished in a very concise manner (3–4 step sequences) with high overall yields from a five-membered endocyclic enecarbamate employing phenylselenenyl bromide as an effective promoter.