Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... Pyrromethenones are prepared by a process involving acylation of an N-aminopyrrole with a suitable acetylenic acid,followed by sequential 5-exo-dig cyclization and 3,5-sigmatropic shift. ... Pyrromethenones of general structure 2 are prepared from pyrrolohydrazides of ...