Highly chemo-, enantio-, and regioselective synthesis of α,α-disubstituted furanones by Cu-catalyzed conjugate addition.

A highly chemo-, enantio-, and regioselective synthesis of furanones bearing an α,α-disubstituted quaternary stereogenic center is reported. The Cu-catalyzed enantioselective conjugate addition of organoaluminum reagents to unsaturated ketoesters at room temperature and subsequent lactonization took place. Synthetic transformations of furanones represent facile approaches to various cyclic or acyclic compounds bearing a quaternary stereogenic center.