| 摘要 |
<p>A method is disclosed for preparing novel guanine PNA synthons having selective carbamate protection of the exocyclic 2-amino group. The exocyclic 2-amino group of a 2-aminopurine is typically non-nucleophilic, therefore the first step of this method involves converting the 2-amino group of a partially protected 2-amino-6-halopurine to a 2-isocyanate group, and subsequently reacting the 2-isocyanate group with an alcohol thereby forming a carbamate protected 2-amino group of a fully protected 2-amino-6-halopurine. Next, the carbamate-protected guanine side-chain moiety is prepared from the fully protected 2-amino-6-halopurine. Thereafter, the guanine PNA synthon ester is assembled by coupling the carbamate protected guanine side chain moiety to a suitably protected backbone ester of the amino acid N-(2-aminoethyl)-glycine. Finally, the backbone ester group is hydrolyzed to produce the novel guanine PNA synthon which is completely consistent with the t-boc/benzyl protection strategy currently employed for PNA synthesis.</p> |
