Photochemistry of a naphthalene-thymine dyad in the presence of acetone

The photobehavior of 1 is dominated by the naphthalene-derived chromophore. In the presence of acetone, this was found to be the photoreactive site, and only 2 was obtained. Thymine dimers and acetone photoadducts involving the thymine ring, which would arise from the thymine triplet excited state, were not detected.