Gold(I)-Catalyzed Domino Reaction for Furopyrans Synthesis.

We report herein an efficient synthesis of furopyran derivatives through a gold(I)-catalyzed domino reaction. The cascade reaction starts with two regioselective cyclizations, a 5-endo-dig and a 8-endo-dig, followed with a Grob-type fragmentation and a hetero Diels-Alder. The obtained furopyran derivatives contain fused and spiro-heterocycles. During this one-pot process, four bonds and four controlled stereogenic centers including a quaternary center are formed.