Stereoisomeric pyrimidine nucleoside analogues based on the 1,3-dihydrobenzo[c]furan core

A new efficient route is described to uracil, thymidine and cytosine derivatives of 1,3-dihydrobenzo[c]furan which are aromatic analogues of the well known antiviral 2',3'-dideoxy-2',3'-didehydronucleosides. These systems contain two chiral centres (corresponding to alpha/beta and D/L centres in a furanose sugar) and a route involving application of the Sharpless asymmetric oxidation methodology allowed access to each of the four stereoisomers of the uracil derivative in enantiomerically pure form.