2-Amino-1,9-dihydro-9-[(4R,5R,7R,8R)-8-hydroxy-7-(hydroxymethyl)-6-oxa-1-thiaspiro[3.4]oct-5-yl]-6H-purin-6-one

2-Amino-9-[(2′R,6aR,8R,9aR)-dihydro-2,2,4,4-tetrakis(1-methylethyl)spiro[6H-furo[3,2-f]-1,3,5,2,4-trioxadisilocin-9(8H),2′-thietan]-8-yl]-1,9-dihydro-6H-purin-6-one

N-[9-[(2′R,6aR,8R,9aR)-Dihydro-2,2,4,4-tetrakis(1-methylethyl)spiro[6H-furo[3,2-f]-1,3,5,2,4-trioxadisilocin-9(8H),2′-thietan]-8-yl]-6,9-dihydro-6-oxo-1H-purin-2-yl]-2-methylpropanamide

1-[(4R,5R,7S,8R)-7-Azido-8-(benzoyloxy)-7-(iodomethyl)-6-oxa-1-thiaspiro[3.4]oct-5-yl]-2,4(1H,3H)-pyrimidinedione

1-[(4R,5R,7S,8R)-7-Azido-8-hydroxy-7-(iodomethyl)-6-oxa-1-thiaspiro[3.4]oct-5-yl]-2,4(1H,3H)-pyrimidinedione

1-[(2S,2′R,4aS,6R,7aR)-2-(Cyclobutylamino)-4a-fluorodihydro-2-oxidospiro[4H-furo[3,2-d]-1,3,2-dioxaphosphorin-7(6H),2′-thietan]-6-yl]-2,4(1H,3H)-pyrimidinedione

1-[(2R,2′R,4aS,6R,7aR)-2-(Cyclobutylamino)-4a-fluorodihydro-2-oxidospiro[4H-furo[3,2-d]-1,3,2-dioxaphosphorin-7(6H),2′-thietan]-6-yl]-2,4(1H,3H)-pyrimidinedione

1-[(2′R,4aS,6R,7aR)-2-(Cyclopentyloxy)-4a-fluorodihydro-2-oxidospiro[4H-furo[3,2-d]-1,3,2-dioxaphosphorin-7(6H),2′-thietan]-6-yl]-2,4(1H,3H)-pyrimidinedione

N-[[[(4R,5R,7S,8R)-5-(4-Amino-2-oxo-1(2H)-pyrimidinyl)-7-fluoro-8-hydroxy-6-oxa-1-thiaspiro[3.4]oct-7-yl]methoxy]phenoxyphosphinyl]-L-alanine 1-methylethyl ester