β-thymidine is a key intermediate in the manufacturing of anti-AIDS agents- AZT and d4 T. A practical and economically viable route to β-thymidine starting from inexpensive D-xylose has been described. This synthetic route is based on a new rearrangement leading to 2,2′-anhydro-formation with concomitant epimerisation at C-3′, observed for the first time in nucleoside chemistry.
