Synthesis and antiviral evaluation of enantiomeric 2′,3′-dideoxy- and 2′,3′-didehydro-2′,3′-dideoxy-4′-thionucleosides

The synthesis and antiviral evaluation of 2′,3′-dideoxy and 2′,3′-didehydro-2′,3′-dideoxy 4′-thionucleosides in both enantiomeric series are described. Enantiomeric 4-O-silylated-4-hydroxymethyl-4-thiobutyrolactones, produced in high yield from chiral glycidols, provided suitable chiral synthons: phenylselenation of these intermediates resulted in anomeric selectivity in nucleobase glycosidations. L-d4-cytidine analogues showed marked anti-HBV and anti-HIV activity.