Patent ID: 7081449

Claim:
A nucleoside analog according to the formula (I) wherein A is O; R 2 , R 2 ′, R 3 , and R 3 ′ are independently selected from H, F, OH, NH 2 , CN, N 3 , CONH 2 , and R, where R is lower alkyl, lower alkenyl, lower alkynyl, or lower acyl; or R 2 and R 2 ′ together, or R 3 and R 3 ′ together are selected from ═CH 2 , ═CHR″, ═CR″ 2 , ═NR″, where R″ is H, F, OH, CN, N 3 , CONH 2 , lower alkyl, lower alkenyl, lower alkynyl, or lower acyl; R 4 is selected from H, lower alkyl, lower alkenyl, lower alkynyl, aralkyl, or hydroxymethyl; R 5 ′ is selected from H, lower alkyl, lower alkenyl, lower alkynyl, or aralkyl; R 5 is H, OH, OP(O)(OH) 2 , or P(O)(OH) 2 ; and B is selected from the group of heterocyclic radicals consisting of formulae (II) and (IV) wherein X is H, NH 2 or OH; Y is H, NH 2 , or halogen; Z 1 is O, S, NR″, CHM, or CM 2 ; Z 3 is N, CH, or CM; Z 2 is N, CH, or CM; where M is F, Cl, Br, OH, SH, NH 2 , CN, COOR″, C(═NH)NH 2 , lower alkyl, lower alkenyl, lower alkynyl, aralkyl, or aryl.