Photosensitized oxidation of furans. Part 4. Influence of the substituents on the behaviour of the endo-peroxides of furans

Abstract

A comparison of the behaviour of endo-peroxides of the β-furoic esters (1a,b and d–f) and of the furans (1c or g), with the same 2,5-substituents, shows that the thermal instability of these compounds is related to the electron density in the bicyclic unsaturated ring. This also accounts for the higher stability of the alkyl-substituted endo-peroxides (1a–c) as compared with that of the aryl-substituted derivatives (1d–g), as well as for the different course of the thermal conversion in the two series.