Synthesis of the new nucleoside analogue connecting 2-amino-6-vinylpurine to the 2'-deoxyribose skeleton via the methylene linker.

We have previously reported that the 2-amino-6-vinylpurine nucleoside exhibits the highly efficient and selective cross-linking reaction toward the cytosine base at the target site in the duplex DNA. The nucleoside analogues that connect the 2-amino-6-vinylpurine to the 2'-deoxyribose skeleton through the ethylene or the butylene linker formed the cross-link selectively to the adenine base of the TA pair or the cytosine base of the GC pair in the triplex DNA, respectively. They did not form cross-link in the duplex DNA. These results lead us to study in detail the relationship between the linker length and the cross-linking ability. In this study, we describe the synthesis of the new nucleoside analogue that connects 2-amino-6-vinylpurine to the 2'-deoxyribose unit via the methylene linker.