Naphthaloyl group: a new selective amino protecting group for deoxynucleosides in oligonucleotide synthesis

The naphthaloyl group has been found to be a selective amino protecting group for deoxycytidine, deoxyadenosine, and deoxyguanosine in oligodeoxyribonucleotide synthesis. All three protected monomers obtained (78–85%), being six-membered cyclic imides, were fairly stable. These protected monomers were used successfully for the preparation of dimers (phosphodiester approach) and tetramers (phosphotriester approach) in solution as well as solid phase, respectively. The group acted as a purification tool due to its high lipophilicity. No adverse effect has been observed either on the glycosidic bond (depurination) or the internucleotidic bond during its removal. The monomeric units were characterized by UV, NMR, and elemental analyses whereas the tetramers were characterized by enzymatic hydrolyses with snake venom phosphodiesterase followed by alkaline phosphatase.