Synthesis of a novel ester analog of nucleic acids bearing a serine backbone

A novel analog of nucleic acids bearing an optically active serine ester backbone, serine-based nucleobase-linked polyester (SNE), was synthesized. Monomers containing a thymine base were synthesized from l- and d-serines. Furthermore, reaction conditions were thoroughly examined for the ester bond formation by using a new phosphonium-type condensing reagent on a solid support without racemization. The release of the dimer from the resin was also investigated using a new type of linker, which could be cleaved under neutral conditions.