Reversible 1,4-cycloaddition of singlet oxygen to N-substituted 2-pyridones: 1,4-endoperoxide as a versatile chemical source of singlet oxygen

Abstract

N-substituted pyridones (1) easily undergo singlet oxygenation to give exclusively the corresponding endoperoxides (2), which decompose to give pyridones again while liberating 1O2 in high yield.