Abstract Cyclization of α-acylhydrazinoacids with dicyclohexylcarbodiimide or with acetic anhydride allows an easy entry to the little known class of 4, 5-dihydro-6H-1, 3, 4-oxadiazin- 6-ones. Such compounds maintain the optical activity of the starting hydrazino acids and may be exploited as useful acylating agents.
