NITROGEN-15-LABELED DEOXYNUCLEOSIDES .4. SYNTHESIS OF [1-N-15]-LABELED AND [2-N-15]-LABELED 2'-DEOXYGUANOSINES

The syntheses of [1-N-15]- and [2-N-15]-2'-deoxyguanosines are reported via transformation of 2'-deoxyadenosine. The N-15 source for the [1-N-15] label is [6-N-15]-2'-deoxyadenosine, while for the [2-N-15] label it is [N-15]KCN. The synthetic route is particularly straightforward in that there are no protection and deprotection steps and only one chromatographic purification. Furthermore, it is directly applicable to preparation of the labeled ribonucleosides. These [1-N-15]- and [2-N-15]-labeled guanine nucleosides are now available by routes that give material in sufficient yields that they can be prepared for incorporation into nucleic acid fragments.