A class of 2′-fluoro-
nucleoside compounds are disclosed which are useful in the treatment of 
hepatitis B infection, 
hepatitis C infection, HIV and abnormal cellular proliferation, including tumors and 
cancer. The compounds have the general formulae: wherein[0001]Base is a 
purine or 
pyrimidine base;[0002]R1 is OH, H, OR3, N3, CN, 
halogen, including F, or CF3, lower 
alkyl, amino, loweralkylamino, di(lower)alkylamino, or alkoxy, and base refers to a 
purine or 
pyrimidine base;[0003]R2 is H, 
phosphate, including monophosphate, diphosphate, triphosphate, or a stabilized 
phosphate prodrug; acyl, or other pharmaceutically acceptable 
leaving group which when administered 
in vivo, is capable of providing a compound wherein R2 is H or 
phosphate; 
sulfonate ester including 
alkyl or arylalkyl 
sulfonyl including methanesulfonyl, benzyl, wherein the 
phenyl group is optionally substituted with one or more substituents as described in the definition of 
aryl given above, a lipid, an 
amino acid, 
peptide, or 
cholesterol; and[0004]R3 is acyl, 
alkyl, phosphate, or other pharmaceutically acceptable 
leaving group which when administered 
in vivo, is capable of being cleaved to the parent compound, or a pharmaceutically acceptable salt thereof.