2-[(Tetrahydropyran-2-yl)oxy]ethyl p-Toluenesulfonate is an intermediate in the synthesis of 9-(2-Hydroxyethyl)guanine (H942035), is an impurity of the antiviral agent Acyclovir (A192400). 9-(2-Hydroxyethyl)guanine is a nucleoside phosphotransferase acceptor.