Reaction of silylated guanine derivatives with 2-acetoxy-4-benzoyloxymethyl
tetrahydrofuran in DMF or NMP resulted in selective N-9 alkylation. This wa
s used as the basis for a regioselective synthesis of the anti-viral agents
famciclovir and penciclovir. (C) 2001 Elsevier Science Ltd. All rights res
erved.