Synthesis of Oligonucleotides Containing the N 6 -(2-Deoxy-α,β-d -erythropentofuranosyl)-2,6-diamino-4-hydroxy-5-formamidopyrimidine (Fapy⋅dG) Oxidative Damage Product Derived from 2′-Deoxyguanosine

N(6) -(2-Deoxy-alpha,beta-d-erythropentofuranosyl)-2,6-diamino-4-hydroxy-5-formamidopy rimidine (FapydG) is a major DNA lesion produced from 2'-deoxyguanosine under oxidizing conditions. FapydG is produced from a common intermediate that leads to 7,8-dihydro-8-oxo-2'-deoxyguanosine (8-OxodGuo), and in greater quantities in cells. The impact of FapydG on DNA structure and function is much less well understood than that of 8-OxodGuo. This is largely due to the significantly greater difficulty in synthesizing oligonucleotides containing FapydG than 8-OxodGuo. We describe a synthetic approach for preparing oligonucleotides containing FapydG that will facilitate intensive studies of this lesion in DNA. A variety of oligonucleotides as long as 30 nucleotides are synthesized. We anticipate that the chemistry described herein will provide an impetus for a wide range of studies involving FapydG.