(((2-(6-Amino-9H-purin-9-yl)ethoxy)methyl)phosphinylidene)bis(oxymethylene) 2,2-dimethylpropanoate 142340-99-6 9-(2-((-Bis((pivaloyloxy)methoxy)phosphinyl)methoxy)ethyl)adenine ADEFOVIR DIPIVOXIL GS 840 GS-0840 Hepsera Propanoic acid, 2,2-dimethyl-, (((2-(6-amino-9H-purin-9-yl)ethoxy)methyl)phosphinylidene)bis(oxymethylene) ester