A New Formal Synthetic Route to Entecavir

We describe a new and straightforward approach to the formal synthesis of the hepatitis B virus inhibitor entecavir, an important hepatitis B drug, in ten steps overall. Key features of the route are a Morita-Baylis-Hillman reaction, a Sharpless asymmetric epoxidation, a reductive epoxide opening of an ,-epoxy ketone, and a Riley selenium dioxide oxidation.