Gold-Catalyzed Propargylic Substitution Followed by Cycloisomerization in Ionic Liquid: Environmentally Friendly Synthesis of Polysubstituted Furans from Propargylic Alcohols and 1,3-Dicarbonyl Compounds

Gold-catalyzed propargylic substitution of propargylic alcohols <b>1</b> with 1,3-dicarbonyl compounds <b>2</b> followed by cycloisomerization in ionic liquid enables the environmentally friendly synthesis of polysubstituted furans <b>3</b> in good-to-high yields. The reaction proceeds via the hydrated propargylic substitution product <b>3″aa</b>. The gold catalyst can be recycled at least three times.