Photochemical intramolecular acylation of 3-(2-hydroxybenzylidene)-4,5-dihydrofuran-2(3H)-one in methanol

Abstract
The dependence of the kinetics on the wavelenghth of trans-3-(2-hydroxybenzylidene)-4,5-dihydrofuran-2(3H)-one was studied at 220–360 nm in methanol solution for the two consecutive photochemical reactions, geometrical isomerization of the trans- and intramolecular acylation of the cis-substrate. Quantum yields for the first reaction were higher (at 5.20 × 10–5 M) than those for the second. The effect of concentration quenching on quantum yields for the latter process was found to be appreciable in the 10–4–10–5 M range. This reaction appears to proceed through long-lived T2 states, while isomerization occurs either directly from the singlet excited state S1 or indirectly by crossing of S1 to a triplet excited state T1.

This publication has 0 references indexed in Scilit: