Catalytic Enantioselective Peroxidation of α,β-Unsaturated Aldehydes for the Asymmetric Synthesis of Biologically Important Chiral Endoperoxides

We have developed an unprecedented highly enantioselective catalytic peroxidation of enals. Critical to this development is the discovery that varying the structure of the hydroperoxide has a significant impact on the enantioselectivity of the organocatalytic asymmetric peroxidation. This novel transformation enabled the development of an enantioselective route toward the core structure shared by all members of the stolonoxide family of anticancer natural products, a connected trans-3,6-disubstituted-1,2-dioxane and trans-2,5-disubstituted-tetrahydrofuran ring system. Our route also features an unprecedented cyclization cascade of a chiral bis(epoxy)-hydroperoxide. The new methodology and synthetic strategy established in this work should be applicable to the enantioselective synthesis of a broad range of chiral 1,2-dioxolanes and 1,2-dioxanes, thereby facilitating biological and medicinal chemistry studies of peroxy natural products.