Synthesis of bromo- and carboxylic acid-substituted methylenepyrans
Résumé
In this contribution we describe a series of pyranylidene derivatives bearing bromine atoms in various positions. Some of these bromo derivatives have been converted in carboxylic acid by halogen-metal exchange reaction using gaseous CO2 as electrophile. Selected compounds have been studied by UV-visible absorption and cyclic voltametry to study the influence of the substituent on the pyranylidene core.