Efficient Access to 2‐Pyrones via Carbene‐Catalyzed Oxidative [3+3] Reactions between Enals and Nitrogen Ylides

Abstract

Abstract Pyrones are important structural units in natural products and synthetic functional molecules. Here, we report a carbene‐catalyzed oxidative [3+3] cycloaddition reaction between enals and nitrogen ylides for quick access to 2‐pyrones. Inexpensive and easily prepared 2′‐pyridinium acetophenone bromide salts are used as precursors of pyridinium ylides to react with enals in our catalytic reactions.