Brønsted Acid Catalyzed Remote Bisvinylogous Initiated Formal [4+2] Cycloaddition Reaction of β‐Allyl Cycloalkenones With in situ Generated Ortho ‐Quinone Methides

In this work, we disclose that β‐allyl cycloalkenones can serve as effective bisvinylogous precursors through in situ generation of trienalcohol intermediates under Brønsted acid catalysis. This strategy enables a direct and highly diastereoselective δ,ε‐regioselective remote bisvinylogous initiated formal [4+2] cycloaddition of β‐allyl cycloalkenones with ortho ‐quinone methides ( o ‐QMs). In this process, β‐allyl cycloalkenones act as dienophiles while o ‐QMs function as diene precursors, providing efficient access to naphthopyran derivatives with excellent selectivity. Additionally, the asymmetric variant was also investigated using a BINOL‐derived chiral Brønsted acid, thereby extending the utility of this method toward enantioselective synthesis.