1	BTD	5-bromothienyldeoxyuridine	1.000
2	DUR	2'-deoxyuridine	0.727
3	THU	Tetrahydrodeoxyuridine	0.727
4	8LK	Pyrrolo-dc	0.708
5	AWC	2'-deoxy-5'-O-[(R)-hydroxy(oxo)-lambda~5~-phosphanyl]-5-selenophen-2-yluridine	0.704