Expeditious Copper-Catalyzed Conjugate 1,4-Addition of Bromo[2-(1,3-dioxolan-2-yl)ethyl]magnesium to α,β-Cycloalkenones and Subsequent Transformations

Expeditious CuI-catalyzed conjugate 1,4-addition of bromo[2-(1,3-dioxolan-2-yl)ethyl]magnesium to the five-, six-, seven-, and eight-membered alpha,beta-cycloalkenones is described. The reaction times are decreased dramatically compared to CuBr-(CH(3))(2)S catalysis. The resulting ketoacetals were subsequently cyclized to bicyclic beta-hydroxy ketones and alpha,beta-enones, followed by further transformations.