The intramolecular [2+2] photocycloaddition of α,β-butenolides to a terminal double bond tethered to the lactone through the γ-position and located at a suitable distance has been studied. The regioselectivity of the photoisomerization depends on the substitution pattern of the substrate and can be rationalized by simple theoretical calculations performed on the diradical intermediates.
|Published - 10 Jul 2001
- Intermediate diradicals
- Intramolecular photochemical cycloaddition