A new synthesis of 3(2<i>H</i>)‐furanones from acetylenic β‐diketones

Abstract

Abstract Thermal cyclization of 1,5‐diarylpent‐1‐yne‐3,5‐diones led to the formation of 2‐benzyliden‐5‐aryl‐3(2 H ) furanones as well as 2,6‐diaryl‐4 H ‐pyran‐4‐ones as minor products. The structure of the furanones was established from their ir, 1 H nmr and mass spectral data. Their reaction with hydrazine hydrate gave pyrazole derivatives.