Nucleotides. Part XXXVI. Syntheses and biological characterization of phosphorothioate analogues of (3′–5′)adenylate trimer

The four protected diastereoisomcrs 7a/7b and 8a/8b P‐thioadenylyl‐(3′–5′)‐P‐thioadenylyI‐(3′–5′)‐adenosine were synthesized, separated, and deblocked to the free oligonucleotides (Scheme). Biochemical characterization of these (3′–5′)phosphorothioate analogues of adenyiate trimer indicate that these compounds, and the corresponding 5′‐monophosphates, neither bind to nor activate RNase L, and are considered to be valuable control compounds in screening experiments.