Gold catalysis in organic synthesis: Efficient intramolecular cyclization of γ-acetylenic carboxylic acids to 5-exo-alkylidene-butyrolactones

Abstract

We have found that functionalized acetylenic acids may be cyclized under extremely mild conditions, at room temperature in the presence of AuCl catalyst and without the use of additives. The corresponding 5-exo-alkylidene- butyrolactones were isolated in high yields, and this process constitutes an easy and efficient route to highly valuable building blocks of natural products having biological interest. ©ARKAT.