A Minute Amount of S-Puckered Sugars Is Sufficient for (6-4) Photoproduct Formation at the Dinucleotide Level.
Résumé
The di-2′-α-fluoro analogue of thymidylyl(3′,5′)thymidine, synthesized to probe the effect of a minimum amount of S conformer on the photoreactivity of dinucleotides, is endowed with only 3% and 8% of S sugar conformation at its 5′- and 3′-end, respectively. This analogue gives rise to the (6-4) photoproduct as efficiently as the dithymine dinucleotide (74% and 66% at the 5′- and 3′-end, respectively) under 254 nm. Our results suggest that the 5′-N, 3′-S conformer gives rise to the (6-4) photoproduct.