A highly efficient chemical synthesis of Rp and Sp adenyl(3′-5′)adenyl-o,o-phosphorothioate

Abstract

A method is described for the chemical synthesis of the title compounds (Ap(S)A) via addition of elemental sulfur to a phosphite triester intermediate. Separation of the diastereomers of phosphorus could be accomplished on silica gel after removal of the terminal 5′-hydroxyl protecting group or on DEAE cellulose after complete deblocking. The triester to terminal 5′-hydroxyl. The overall yield of the synthesis (one coupling and four deblocking steps) is 30%.