Protection of the amino group of adenosine and guanosine derivatives by elaboration into a 2,5-dimethylpyrrole moiety.

[reaction: see text] Protection of the amino group of adenine and guanine nucleosides was effected by heating the substrates in 2,5-hexanedione. The resulting 2,5-dimethylpyrrole adducts were stable toward bases but were hydrolyzed with TFA/H(2)O to regenerate the amino function.