Synthesis of Nucleoside 3′-Thiophosphates in One Step Procedure

Abstract

A mild and efficient one-step method of thiophosphorylation was devised for acid-sensitive nucleosides. The procedure is based on thiophosphorylation of nucleoside magnesium alkoxide by 2-chloro-2-thio-1,3,2-dioxaphospholane. The utility and efficiency of this method combined with deprotection of the resulting cyclic triester were demonstrated by its application to the synthesis of both adenosine 3′- and 5′-thiophosphates. The procedure does not require protection of the exocyclic amino group and can be successfully used for the thiophosphorylation of nucleosides that are unusually sensitive to depurination.