Purification Methods

Purify -pyrone by vacuum distillation; the distillate crystallises and is hygroscopic. It is non-steam vola

General Description

4H-Pyran-4-one (also known as 4-pyrone, gamma-pyrone, or pyran-4-one) is a heterocyclic compound that can be synthesized via [4+2]-cycloaddition reactions of ketenes with electron-rich conjugated dienes, followed by rearrangement of the intermediate dihydropyrans. This method provides a streamlined, one-step approach to 4-pyrones, contrasting with conventional multi-step syntheses. The reaction proceeds through a dipolar intermediate stabilized by electron-donating substituents on the diene, demonstrating broad applicability for ketenes and suitably substituted dienes.

Definition

ChEBI: A pyranone that is 4H-pyran substituted by an oxo group at position 4.