3-Aryl glutaric acid anhydrides have been explored as substrates for the Castagnoli-Cushman reaction with imines. A series of 3-aryl glutaric acids was synthesized according to literature protocols and introduced into the reaction with imines in the presence of acetic anhydride. The latter acted as a dehydrating agent leading to in situ generation of a cyclic anhydride from the dicarboxylic acid starting material. Reassuringly, the reaction gave the desired δ-lactams with three newly created stereocenters as predominantly one diastereomer whose relative configuration was established by single-crystal X-ray crystallography.