Construction of Bridged-Ring-Fused Naphthalenone Derivatives Through an Unexpected Zn(OTf)2-Catalyzed Cascade Transformation

An unexpected cascade transformation of aminonaph-thoquinones with N-substituents bearing a p-methoxybenzyl ether into bridged-ring-fused naphthalenone derivatives is reported. This cascade transformation was initiated by a catalytic amount of Zn(OTf)(2) and involved with subsequent functional group migration and cyclization. The process proceeded through the cleavage of two bonds and the formation of three new bonds in one pot and was proven to be efficient and tolerant to various substituents.