Catalytic Three-Component Synthesis of FunctionalizedNaphtho[2,1‑ b ]oxecines via a Double Bond Cleavage–RearrangementCascade

A new double annulation cascade involving a [2 + 2] cycloaddition–retroelectrocyclization (CA–RE) process was first reported, leading to the generation of unprecedented dibenzoannulated naphtho[2,1-b]oxecines with good to excellent yields and high stereoselectivity through catalytic scission/recombination of C–C double bonds under the mild conditions. An Y(OTf)3-catalyzed three-component reaction of α-alkynyl naphthalen-2-ols with β,γ-unsaturated α-ketoesters enabled direct ring expansion of the naphthalene ring and carbon–carbon double bond cleavage/rearrangement of α-ketoesters to give macrocyclic architectures.