?6H-Purin-6-one,2-amino-1,9-dihydro-9-[(1S,3R,4S)-2-methylene-4-(phenylmethoxy)-3-[(phenylmethoxy)methyl]cyclopentyl]- , its cas register number 142217-81-0. It also can be called?2-Amino-1,9-dihydro-9-[(1S,3R,4S)-4-(benzyloxy)-3-(benzyloxymethyl)-2-methylenecyclopentyl]-6H-purin-6-one .