for the following products
9-(2-Diisopanoxyphosphonylmethoxyethyl)adenine | 9-[2-(Diethylphosphonomethoxy)ethyl]adenine | Diethyl ((2-(6-amino-9H-purin-9-yl)ethoxy)methyl)phosphonate and [[2-(6-Amino-9H-purin-9-yl)ethoxy]methyl] phosphonic acid diethyl ester
