5′-O-[[[6-[[2-(1,4-Dihydro-2,4-dioxo-3(2H)-quinazolinyl)acetyl]amino]hexyl]oxy]hydroxyphosphinyl]thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidine

5′-O-[Hydroxy[[6-[[[1,2,3,4-tetrahydro-3-(1-naphthalenyl)-2,4-dioxo-7-quinazolinyl]carbonyl]amino]hexyl]oxy]phosphinyl]thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidine

5′-O-[[[6-[[(3-Ethyl-1,2,3,4-tetrahydro-2,4-dioxo-7-quinazolinyl)carbonyl]amino]hexyl]oxy]hydroxyphosphinyl]thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidine

5′-O-[Hydroxy[[6-[[(1,2,3,4-tetrahydro-5-methyl-2,4-dioxopyrido[2,3-d]pyrimidin-7-yl)carbonyl]amino]hexyl]oxy]phosphinyl]thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidine

5′-O-[Hydroxy[[6-[[(1,2,3,4-tetrahydro-1-methyl-2,4-dioxopyrido[2,3-d]pyrimidin-6-yl)carbonyl]amino]hexyl]oxy]phosphinyl]thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidine

5′-O-[Hydroxy[[6-[[(1,2,3,4-tetrahydro-2,4-dioxopyrido[2,3-d]pyrimidin-6-yl)carbonyl]amino]hexyl]oxy]phosphinyl]thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidine

5′-O-[[[6-[[3-(3,4-Dihydro-2,4-dioxo-1(2H)-pyrimidinyl)-1-oxopropyl]amino]hexyl]oxy]hydroxyphosphinyl]thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidine

5′-O-[[[6-[[2-(3,4-Dihydro-2,4-dioxo-1(2H)-pyrimidinyl)acetyl]amino]hexyl]oxy]hydroxyphosphinyl]thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidine

5′-O-[Hydroxy[[6-[[(1,2,3,4-tetrahydro-1-methyl-2,4-dioxo-5-pyrimidinyl)carbonyl]amino]hexyl]oxy]phosphinyl]thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidine

5′-O-[Hydroxy[[6-[[(1,2,3,4-tetrahydro-3-methyl-2,4-dioxo-5-pyrimidinyl)carbonyl]amino]hexyl]oxy]phosphinyl]thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidine

5′-O-[Hydroxy[[6-[[(1,2,3,6-tetrahydro-2,6-dioxo-4-pyrimidinyl)carbonyl]amino]hexyl]oxy]phosphinyl]thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidine

5′-O-[Hydroxy[[6-[[(1,2,3,4-tetrahydro-2,4-dioxo-5-pyrimidinyl)carbonyl]amino]hexyl]oxy]phosphinyl]thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidine

5′-O-[[[6-[[(3,4-Dihydro-5,6-dimethyl-3-oxo-2-pyrazinyl)carbonyl]amino]hexyl]oxy]hydroxyphosphinyl]thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidine

5′-O-[[[6-[[(3,4-Dihydro-5-methyl-4-oxothieno[2,3-d]pyrimidin-6-yl)carbonyl]amino]hexyl]oxy]hydroxyphosphinyl]thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidine

5′-O-[[[6-[[(3,4-Dihydro-3,5-dimethyl-4-oxothieno[2,3-d]pyrimidin-6-yl)carbonyl]amino]hexyl]oxy]hydroxyphosphinyl]thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidine

5′-O-[[[6-[[2-[(3,4-Dihydro-4-oxo-2-quinazolinyl)methoxy]acetyl]amino]hexyl]oxy]hydroxyphosphinyl]thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidine

5′-O-[Hydroxy[[6-[[3-(4,5,6,7-tetrahydro-4-oxo-1H-cyclopenta[4,5]thieno[2,3-d]pyrimidin-2-yl)-1-oxopropyl]amino]hexyl]oxy]phosphinyl]thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidine

5′-O-[[[6-[[4-(3,4-Dihydro-4-oxo-2-quinazolinyl)-1-oxobutyl]amino]hexyl]oxy]hydroxyphosphinyl]thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidine

5′-O-[Hydroxy[[6-[[1-oxo-3-(4-oxo-3(4H)-quinazolinyl)propyl]amino]hexyl]oxy]phosphinyl]thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidine

5′-O-[[[6-[[3-(3,4-Dihydro-3-oxo-2-quinoxalinyl)-1-oxopropyl]amino]hexyl]oxy]hydroxyphosphinyl]thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymidine