Acyclic analogs of thymidine, cytidine, and adenosine containing cis-5
-hydroxy-2-pentene instead of the ribose ring were synthesized by cond
ensation of 1-bromo-cis-5-acetoxy-2-pentene with nucleic bases. Their
triphosphates were also synthesized to assess the ability of the hydro
xypentene nucleoside derivatives to act as termination substrates in D
NA synthesis by DNA polymerases.