Transition‐metal free synthesis of 2‐pyrones by [3 + 3] annulation of cyclopropenones and sulfur ylides

Abstract A simple and efficient synthesis for 2‐pyrones by [3 + 3] annulation of cyclopropenones and sulfur ylides in the presence of triethyl amine as a base has been developed featuring transition‐metal free conditions, high yields, and excellent functional group compatibility. Using this process, a variety of 2‐pyrones were prepared in good to excellent yields.