Study on disulfur-backboned nucleic acids: Part IV. Efficient synthesis of 3′,5′-dithio-2′-deoxyguanosine

An efficient and novel method for synthesizing 3′,5′-dithio-2′-deoxyguanosine was described. In this method normal guanosine was used as the starting material. A very efficient procedure was used to synthesize 2́-O-tosylguanosine 1, which used 0.1 eq. DBTO instead of 2 eq. 1 was treated with LTBH to give 9-(2-deoxy-β-d-threo-pentofuranosyl)guanine 2. 2 could be easily turned to the target compound.