Continuing our search for biologically active compounds based on substituted lactones, we have accomplished several chemical transformations that lead to new systems that contain heterocyclic (lactone, lactam, etc) rings. Thus the reaction of 3-cyano-4, 5, 5-trimethyl-A3- butenelide (I) with amines led to the corresponding amidines containing lactone or lactam rings (V-VIII); by the action of bromine on 3-acetyl-4, 5, 5-trimethyl-A3-butenolide (II) we ...