Conversion of Nucleoside H-Phosphonate Monoesters to the Corresponding H-Phosphonothioates. ³¹P NMR Studies

Abstract

³¹P NMR Studies on the conversion of nucleoside H-phosphonate monoesters into the corresponding H-phosphonothioates revealed that the key intermediate, the nucleoside trimethylsilyl pivaloyl phosphite 3, may undergo under the reaction conditions at least two parallel transformations to, most likely, the nucleoside trimethylsilyl chlorophosphite 6 and the monosilylated nucleoside H-phosphonate 5.