Therapeutic furopyrimidines and thienopyrimidines

1. The compound 4-Amino-7-β-(2′-C-methyl-D-ribofuranosyl)-furo[3,2-d]pyrimidine; or a pharmaceutically acceptable salt or prodrug thereof.

2. The compound of claim 1 which is a prodrug.

3. The compound of claim 2 which comprises one or more mono-, di-, or tri-phosphate groups.

4. The compound of claim 2 which comprises one or more mono-phosphate groups.

5. The compound of claim 3 wherein one or more pendent hydroxyl groups from the mono-, di-, or tri-phosphate group has been converted to an alkoxy, substituted alkoxy, aryloxy, or substituted aryloxy group.

6. The compound of claim 3 wherein one or more pendent hydroxyl groups from the mono-, di-, or tri-phosphate group has been converted to a group R y —O—; wherein each R y is independently a 1-20 carbon branched or unbranched, saturated or unsaturated chain, wherein one or more of the carbon atoms is optionally replaced with —O— or —S— and wherein one or more of the carbon atoms is optionally substituted with oxo (═O) or thioxo (═S).

7. The compound of claim 3 wherein one or more pendent hydroxyl groups from the mono-, di-, or tri-phosphate group has been converted to a group R z —N—; wherein each R z is a residue of an amino acid.

8. The compound of claim 7 wherein the amino acid is a natural amino acid.

9. The compound of claim 3 which comprises one or more groups of formula:

wherein:

R 15 is H, alkyl, substituted alkyl, aryl, substituted aryl, cycloalkyl, substituted cycloalkyl, heteroaryl, substituted heteroaryl, heterocyclic, substituted heterocyclic, or an amino acid;

R 16 is H, optionally substituted monocyclic aryl, or optionally substituted monocyclic heteroaryl; and R 17 is H, halogen, CN, —CO—R 20 , —CON(R 21 ) 2 , —CO 2 R 20 , —SO 2 R 20 , —SO 2 N(R 21 ) 2 , —OR 21 , —SR 21 , —R 21 , —N(R 21 ) 2 , —O—COR 20 , —O—CO 2 R 20 , —SCOR 20 , —S—CO 2 R 20 , —NHCOR 21 , —NHCO 2 R 21 , —(CH 2 ) p —OR 22 , or —(CH 2 ) p —SR 22 ; or R 16 and R 17 are connected via an additional 3-5 atoms to form a cyclic group, optionally containing one heteroatom, that is fused to an aryl group at the beta and gamma position to the O attached to the phosphorus; or R 17 and R 18 are connected as described below;

R 18 and R 19 are each independently H, alkyl, aryl, heterocycloalkyl, aralkyl, optionally substituted monocyclic aryl or optionally substituted monocyclic heteroaryl; or R 18 and R 19 are connected via an additional 2-5 atoms to form a cyclic group, optionally containing 0-2 heteroatoms; or R 17 and R 18 are connected via an additional 3-5 atoms to form a cyclic group, optionally containing one heteroatom and R 19 is H, alkyl, aryl, heterocycloalkyl, aralkyl, optionally substituted monocyclic aryl or optionally substituted monocyclic heteroaryl;

R 20 is alkyl, aryl, heterocycloalkyl, or arylalkyl;

R 21 is H, alkyl, aryl, heterocycloalkyl, or arylalkyl;

R 22 is H or lower acyl;

n is an integer from 2-5;

m is an integer from 10-20; and

p is an integer from 2-3.

10. A pharmaceutical composition comprising a compound as described in claim 1 ; or a pharmaceutically acceptable salt or prodrug thereof and a pharmaceutically acceptable carrier.

11. The composition of claim 10 which further comprises one or more additional anti-viral agents.

12. The composition of claim 11 wherein the one or more anti-viral agents are selected from ribavirin, levovirin, viramidine, thymosin alpha-1, an inhibitor of a serine proteases, an inhibitor of inosine monophosphatedehydrognease, interferon-α, and pegylated interferon-α (peginterferon-α).

13. The composition of claim 10 which further comprises one or more additional HCV polymerase inhibitors.

14. The composition of claim 10 which further comprises one or more protease inhibitors.

15. The composition of claim 10 which further comprises ribavirin.

16. The composition of claim 10 which further comprises interferon-α or pegylated interferon-α (peginterferon-α).