Compounds represented by the formula (I) R is H, OH,
alkyl, O-
alkyl, CH2—O-
alkyl, (CH2)nOH, (CH2)nNH2, (CH2)nCONH2, (CH2)nOOOH; R1 is H, OH, alkyl, O-alkyl, CH2—O-alkyl, C6H11, CH2OH; R2 is H, alkyl, OH, CH2OH, CH2—O-alkyl, CH(OH)-alkyl, CH(OH)CH2OH, CH2-
halogen; R3 and R4 independently is H, OH, alkyl; Z is OR5, OR6, or aminoacids and esters thereof R5 and R6 independently is H, alkyl,
aryl, pivaloyloxymethyl, C(R7)2OC(O) X (R8)a formula (II), R7 independently is —H, C1-C12 alkyl, C5-C12
aryl, C2-C12 alkenyl, C2-C12 alkynyl, C7-C12 alkenylaryl, C7-C12 alkynylaryl, or C6-C12 alkaryl, any of which is unsubstituted or is substituted with 1 or 2 halo, cyano, azido, nitro, or —OR9; R9 is C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl or C5-C12
aryl; provided that at least one R8 is not H; and a is 1 when X is CH2, or direct bond, or 1 or 2 when X is N with the proviso that when a is 2 and X is N, (a) two N-linked R groups can be taken together to form a carbocyclic or
oxygen containing heterocycle, (b) one N-linked R8 additionally can be —OR9 or (c) both N-linked R8 groups can be —H; R10 is H or C1-C8 alkyl; R11 is selected from H, alkyl, alkenyl, alkynyl, aryl, acyloxyalkyl, and pivaloyloxyalkyl n is 1-5 m is 0 to 5 X is S, N(R8) or direct bond Y is O, S, N (R8), and CHR1 B is selected from the group consisting of adenine,
guanine,
cytosine,
uracil,
thymine, modified purines and pyrimidines such as inosin-9-yl, 2-amino-purin-9-yl, 2amino-6-chloro-purin-9-yl, 2-6-diamino-purin-9-yl, 3-carboxamido-1, 2, 4-triazol-1-yl, 3-deaza-adenin-9-yl, 3-deaza-guanin-9-yl, 3-deaza-inosin-9-yl, 3-deaza-2-amino-purin-9-yl, 3-deaza-2-amino-6-chloro-purin-9-yl, 3-deaza-2, 6-diamino-purin-9-yl, 7-deaza-adenin-9-yl, 7-deaza-guanin-9-yl, 7-deaza-inosin-9-yl, 7-deaza-2-amino-purin-9-yl, 7-deaza-2-amino-6-chloro-purin-9-yl, 7-deaza-2-6-diamino-purin-9-yl, 7-deaza-8-aza-adenin-9-yl, 7-deaza-8-aza-guanin-9-yl, 7-deaza-8-aza-inosnin-9-yl, 7-deaza-8-aza-2-amino-purin-9-yl, 7-deaza-8-aza-2-amino-6-chloro-purin-9-yl, 7-deaza-8-aza-2-6-diamino-purin-9-yl, -8-aza-adenin-9-yl,-8-aza-guanin-9-yl, -8-aza-inosnin-9-yl, -8-aza-2-amino-purin-9-yl, -8-aza-2-amino-6-chloro-purin-9-yl, -8-aza-2-6-diamino-purin-9-yl, 5-aza-thymin-1-yl, 5-aza-cytosin-1-yl, 5-aza-
uracil-1-yl, 6-aza-thymin-1-yl, 6-aza-cytosin-1-yl, 6-aza-
uracil-1-yl, 2-
thiouracil-1-yl, 4-
thiouracil-1-yl, 2 thiocytosine-1-yl, uracil-5-yl, 2-
thiouracil-5-yl, 4-thiouracil-5-yl, substituted
pyridine derivatives such as 6-azauracil, and azacyzosine. In general, attachment may be at different positions in the ring at
nitrogen or carbon. These B ring systems may be substituted with halo, alkyl, substituted alkyl (F, Cl, Br, I, OH), NH2, N3, aryl, substituted aryl (F, Cl, Br, I, OH, NH2), aralkyl; and pharmaceutically acceptable salts thereof and prodrugs thereof are provided.