Efficient Oxa-Diels–Alder/Semipinacol Rearrangement/Aldol Cascade Reaction: Short Approach to Polycyclic Architectures

A novel carbon electrophile induced intermolecular oxa-Diels–Alder/semipinacol rearrangement/aldol cascade reaction of allylic silyl ether with β,γ-unsaturated α-ketoester has been developed under the promotion of SnCl4. This highly efficient transformation enables the quick construction of polycyclic architectures with up to five contiguous stereogenic centers in a single operation with moderate to good yields as well as high diastereoselectivity and would provide versatile short approaches to frameworks and/or analogues of numerous biologically important polycyclic natural products.