Room temperature zinc chloride-catalyzed cycloisomerization of Alk-3-yn-1-ones: synthesis of substituted furans

Abstract

[structure: see text]. 5-Endo-dig cycloisomerization of 1,4-di- and 1,2,4-trisubstituted but-3-yn-1-ones in the presence of a catalytic amount of zinc chloride (10 mol %) in dichloromethane at room temperature (22 degrees C) provides 2,5-di- and 2,3,5-trisubstituted furans in high yields (85-97%).