Synthesis of 3'-fluoro-2',3'-dideoxy-2',3'-didohydro-4'-ethynyl-D- and -L-furanosyl nucleosides

The synthesis of 3'-fluoro-2',3'-dideoxy-2',3'-didehydro-4'-ethynyl D- and L-furanosyl nucleosides, starting from 2,3-O-isopropylidene-D-glycer-aldehyde, is reported. The newly synthesized 4'-substituted nucleosides are tested for their activities against HIV, among which the D-adenine derivative showed moderate anti-HIV activity without significant cytotoxicity.