Patent ID: 8017762

Claim:
An iRNA agent comprising a first strand and optionally a second strand, wherein at least one subunit having the formula below is incorporated into at least one of the strands: wherein: X is N(CO)R 7 , or NR 7 ; Each of R 1 , R 3 , and R 9 is, independently, H, OH, OR a , OR b , CH 2 OR a , or CH 2 OR b , provided that at least one of R 1 , R 3 , and R 9 is OH, OR a , or OR b and that at least one of R 1 , R 3 , and R 9 is CH 2 OR a , or CH 2 OR b ; R 7 has the formula R d -(E′) s -Δ-(E′) t− ; wherein: each of E′ and E″ is a terminal linking group; Δ is a hydrocarbon chain that includes one or more internal linking groups, G, wherein at least one G is —SS—; and each of s and t is, independently, 0 or 1; provided that one of s or t is 1; and R d is H or a ligand; R a is R b is each of A and C is, independently, O or S; and B is OH, O − , or