2-Amino-9-{5-[2-(6-amino-purin-9-yl)-4-hydroxy-5-hydroxymethyl-tetrahydro-furan-3-yloxymethoxymethyl]-3,4-dihydroxy-tetrahydro-furan-2-yl}-1,9-dihydro-purin-6-one AIDS-082157 AIDS082157 rArG(2'-5'-formacetal)