Purines. LXXIX. Synthesis and Hydrolysis of 3-Methoxyadenine and Its N6-Benzyl Derivative Leading to the Corresponding 2-Hydroxyadenines.

Methylation of adenine 3-oxide (8a) with MeI in AcNMe2 afforded 3-emthoxyadenine (9a) in 44% yield. This compound (9a) underwent hydroxide-ion attack at the 2-position to give 2-hydroxyadenine (isoguanine) (10a) in 38% yield. A parallel reaction sequence starting from N6-benzyladenine 3-oxide (8c) and proceeding through N6-benzyl-3-methoxyadenine (9c) provided N6-benzyl-2-hydroxyadenine (10c) in 29% overall yield, together with a small amount of N6-benzyladenine (11c).