Nucleotides. Part LVI. Synthesis and biological activity of modified (2′–5′)triadenylates containing 2′‐terminal 2′,3′‐dideoxy‐3′‐fluoroadenosine derivatives

Some new (2′–5′)triadenylates 13 – 16 , containing at the 2′‐terminal end 3′‐fluoro‐2′,3′‐dideoxyadenosine derivatives, have been synthesized by the phosphotriester method. The selectively blocked nucleosides 2 , 4 , 5 , and 7 , were synthesized from the corresponding unprotected nucleosides 1 , 3 , and 6 . The synthesized trimers 13 , and 14 were 4‐ and 8‐fold, respectively, more stable towards phosphodiesterase from Crotalus durissus than the natural trimer 17 . In comparison to trimer 17 the new compounds 13 – 15 inhibit HIV‐1 reverse transcriptase (RT) activity, and 15 and 16 the HIV‐1 induced syncytia formation 2–3 fold whereas none of 13 – 16 can improve R Nase L activity.