Synthesis of acetylenic β‐diketones and their conversion into 4<i>H</i>‐pyran‐4‐ones, pyrazoles, and 1‐hydroxy‐4‐pyridones

Abstract

Abstract A simple method for the synthesis of acetylenic β‐diketones is described. They can be cyclized to the corresponding 4 H ‐pyran‐4‐ones with acids. Their reaction with hydrazine hydrate gave pyrazole derivatives isomeric with those obtained from 4 H ‐pyran‐4‐ones. With hydroxyl‐amine hydrochloride in ethanol, 1‐hydroxy‐4‐pyridones are formed.