(4R,5S,6R)-di-tert-butyl 7-benzyl-4-((R)-3-(benzyloxy)-1-iodopropyl)-2,8-bis((tert-butoxycarbonyl)imino)-6-((carbamoyloxy)methyl)tetrahydro-1H-purine-3,9(2H,4H)-dicarboxylate

tert-butyl (3aS,4R,10R,10aR)-2,6-bis((tert-butoxycarbonyl)imino)-4-((carbamoyloxy)methyl)-10-(2-hydroxyethyl)-8-oxohexahydro-1H,8H,10H-oxazolo[3,4-c]purine-1-carboxylate

tert-butyl (2E,3aS,4R,6E,10S,10aR)-2,6-bis((tert-butoxycarbonyl)imino)-4-((carbamoyloxy)methyl)-10-hydroxyoctahydro-1H,8H-pyrrolo[1,2-c]purine-1-carboxylate