Photocyclization of cinnamylnaphthols

Article abstract of DOI:10.1016/S0040-4020(98)00147-1

The naphtholic chromophore is responsible for the photophysical and photochemical properties of cinnamylnaphthols le, f. Both fluorescence emission and photocyclization occur from the naphtholic singlet excited slates. The formation of five- and six- membered ring products (2e and 3e, f) is shown to involve a proton transfer mechanism. The low efficiency of trans to cis isomerization is explained as the result of deactivation of the styrenic triplet via intramolecular energy transfer. The resulting naphtholic triplets behave as energy sinks.