Stereospecific coupling reaction for internucleotide methyl phosphonothioate linkage

Article abstract of DOI:10.1016/S0040-4039(00)94646-X

The (Sp)- and (Rp)- diastereomers of 5′-dimethoxytritylthymidyl-(3′-5′)methylphosphono-5′- thio-3′-acetylthymidine were prepared by the stereospecific reaction of 5′-deoxy-5′-iodo-3′-acetylthymidine with the (Sp)- or (Rp)- diastereomers of 5′-dimethoxytritylthymidyl-3′ methylphosphonothioate (Li⁺ salt) in DMF. At 50°C, the coupling reaction was complete within 6 hours.