ChemInform Abstract: Ring Transformations of 3‐(Diethylamino)‐5‐chloro‐2(1H)‐pyrazinones and the Corresponding 2H‐1,4‐Oxazin‐2‐ones on Reaction with Acetylenic Compounds.

Abstract

RingTransformations of 3-(Diethylamino)-5-chloro-2(1H)pyrazinones and the Corresponding 2H-1,4-Oxazin-2-ones on Reaction with Acetylenic Compounds.-The pyrazinones (IIa) -(IIc) and (IV) or the 1,4-oxazinones (IId) and (IIe) react with the acetylenes (I) to undergo a cycloaddition process, followed by cleavage and rearrangement, forming the pyridinones (IIIa) -(IIIc) and (V) and the pyranones (IIId) and (IIIe). (Mechanism). -(TUTONDA, M. G.; VANDENBERGHE, S. M.; VAN AKEN, K. J.; HOORNAERT, G.