Pericyclic Reactions for Anti-HPV Antivirals: Unconventional Nucleoside Analogue Synthesis via Nitrosocarbonyl Chemistry

A new adenine derivative is prepared through the chemistry of
nitrosocarbonyl intermediates. The synthesis relies upon the
functionalization of adenine by inserting an ester moiety, to be
transformed into the corresponding hydroxamic acid. The
oxidation conducted in situ in the presence of cyclopentadiene
afforded the hetero Diels-Alder cycloadduct, furtherly elaborated
to give the target nucleoside analogue. This single
product displayed a selective high activity against HPV. The
EC50 and EC90 values are remarkably lower than the values
collected for Cidofovir used as control drug. The EC50 is 39
times lower while the CC50 value is 97.11 mM.