Synthesis of (4 R,5R)-4-(N -methyl-hydroxyamino)-5-( tert -butyldiphenylsiloxymethyl)-3,4-dihydro-2(5H)-furanone,key intermediate for a series of nucleoside analogs,was studied.

Six nucleoside analogs (nucleoside with two sugars) were determinde by HRFAB MS.

The recent progress of nucleoside analogues as anticancer agents is reviewed.

In this article,we reviewed current anti-HBV drugs,such as interferon,nucleoside analogue,immunomodulatory drugs and gene therapy in the aspects of pharmacologic action and clinical therapeutic effects.

The nucleoside analogue such as ara\|C and CNDAC exert their antitumor activities through incorporation into DNA strand, inhibiting DNA synthesis and causing the cell kill.

The efficacy of nucleosides plus artificial liver support system on treating chronic severe hepatitis;

5 mg and with lamivudine 100 mg were well tolerated,and compared to none-nucleoside analogues treated patients,had no significantly difference in survival rate(P＞0.

Clinical studies have proven that nucleoside analogues(NAs),especially lamivudine,are effective in the inhibition of decompensated chronic hepatitis B,obstructing inflammation induced by HBV replication in short term and decreasing the onset of disease or decompensation of the liver in long term.