5′-O-[Hydroxy[[6-[(triphenylmethyl)thio]hexyl]oxy]phosphinyl]thymidylyl-(3′→5′)-thymidylyl-(3′→5′)-2′-deoxy-5-(1-propyn-1-yl)cytidylyl-(3′→5′)-2′-deoxy-5-(1-propyn-1-yl)cytidylyl-(3′→5′)-2′-deoxy-5-(1-propyn-1-yl)cytidylyl-(3′→5′)-2′-deoxy-5-(1-propyn-1-yl)cytidylyl-(3′→5′)-thymidylyl-(3′→5′)-thymid...