Aryl <i>H-</i>Phosphonates. 12. Synthetic and <sup>31</sup>P NMR Studies on the Preparation of Nucleoside <i>H-</i>Phosphonothioate and Nucleoside <i>H-</i>Phosphonodithioate Monoesters
Transformation of nucleosideH-phosphonate monoesters into the corresponding H-phosphonothioate and H-phosphonodithioate derivatives and possible side-reactions that may accompany this process were studied using (31)P NMR spectroscopy. These provided new insight into a possible mechanism involved in this transformation and constituted the basis for development of efficient methods for the preparation of nucleoside