N-[[[(4R,5R,7S,8R)-5-[4-[[Bis(4-methoxyphenyl)phenylmethyl]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

4-[[Bis(4-methoxyphenyl)phenylmethyl]amino]-1-[(4R,5R,7S,8R)-7-fluoro-8-hydroxy-7-(hydroxymethyl)-6-oxa-1-thiaspiro[3.4]oct-5-yl]-2(1H)-pyrimidinone

1-[(4R,5R,7S,8R)-8-(Benzoyloxy)-7-[(benzoyloxy)methyl]-7-fluoro-6-oxa-1-thiaspiro[3.4]oct-5-yl]-4-[[bis(4-methoxyphenyl)phenylmethyl]amino]-2(1H)-pyrimidinone

4-Amino-1-[(4R,5R,7S,8R)-7-fluoro-8-hydroxy-7-(hydroxymethyl)-6-oxa-1-thiaspiro[3.4]oct-5-yl]-2(1H)-pyrimidinone

4-Amino-1-[(4R,5R,7S,8R)-8-(benzoyloxy)-7-[(benzoyloxy)methyl]-7-fluoro-6-oxa-1-thiaspiro[3.4]oct-5-yl]-2(1H)-pyrimidinone

N-[[[(4R,5R,7S,8R)-5-(3,4-Dihydro-2,4-dioxo-1(2H)-pyrimidinyl)-7-fluoro-8-hydroxy-6-oxa-1-thiaspiro[3.4]oct-7-yl]methoxy]phenoxyphosphinyl]-L-alanine 1-methylethyl ester

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

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

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

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

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

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

4-[[Bis(4-methoxyphenyl)phenylmethyl]amino]-1-[(4R,5R,7R,8R)-8-hydroxy-7-(hydroxymethyl)-6-oxa-1-thiaspiro[3.4]oct-5-yl]-2(1H)-pyrimidinone

4-[[Bis(4-methoxyphenyl)phenylmethyl]amino]-1-[(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]-2(1H)-pyrimidinone

4-Amino-1-[(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]-2(1H)-pyrimidinone

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

(4R,5R,7R,8R)-5-(4-Amino-2-oxo-1(2H)-pyrimidinyl)-7-[(2-methyl-1-oxopropoxy)methyl]-6-oxa-1-thiaspiro[3.4]oct-8-yl 2-methylpropanoate

(4R,5R,7R,8R)-5-(3,4-Dihydro-2,4-dioxo-1(2H)-pyrimidinyl)-7-[(2-methyl-1-oxopropoxy)methyl]-6-oxa-1-thiaspiro[3.4]oct-8-yl 2-methylpropanoate

N-[[[(4R,5R,7R,8R)-5-(3,4-Dihydro-2,4-dioxo-1(2H)-pyrimidinyl)-8-hydroxy-6-oxa-1-thiaspiro[3.4]oct-7-yl]methoxy]phenoxyphosphinyl]-L-alanine 1-methylethyl ester

1-[(4R,5R,7R,8R)-8-Hydroxy-7-(hydroxymethyl)-6-oxa-1-thiaspiro[3.4]oct-5-yl]-2,4(1H,3H)-pyrimidinedione