A process for manufacturing chromenes intended for the preparation of thermosetting resins, includes transforming an aromatic propargyl ether of general formula (I) into a chromene by homogeneous gold(I) catalysis with the catalyst (acetonitrile)[(2-biphenyl)di-tert-butylphosphine]gold(I) hexafluoroantimonate in an organic solvent under an inert or non-inert atmosphere. Moreover, a process for preparing a material made of thermoset resin, includes successively a) implementation of the above process; polymerization of the reaction product obtained in step a) so as to obtain the material made of thermoset resin; c) recovery of the material made of thermoset resin obtained in step b).