Gold( i )-catalyzed asymmetric [3 + 2]-cycloadditions of γ-1-ethoxyethoxy-propiolates and aldehydes

A gold-catalyzed asymmetric intermolecular [3 + 2]-cycloaddition of γ-1-ethoxyethoxy-propiolate and aldehydes by using the chiral ligand 5a or 5b is developed, which provides facile access to highly substituted 2,5-dihydrofurans in up to 84% yield with up to 97% ee.