Mild and Facile Deprotection for the Synthesis of Oligodeoxynucleotide Incorporating a 6-O-Ethyl-deoxyguanosine

The phenoxyacetyl (Pac) group proved to be useful for the synthesis of oligodeoxyribonucleotides incorporating a 6-O-ethylguanine. Since the Pac group could be removed by mild treatment with ammonia, formation of a 2, 4-diaminopurine derivative was avoided. Moreover, the use of the Pac group resulted in significant suppression of the depurination of 6-O-ethyldeoxyguanosine.