Donor–Acceptor Cyclopropane Ring Expansion to 1,2-Dihydronaphthalenes. Access to Bridged Seven-Membered Lactones

A Lewis-acid-promoted domino ring-opening cyclization of readily available donor–acceptor cyclopropanes with a preinstalled electrophilic center, embedded in a donor group, to functionalized 1,2-dihydronaphthalenes is reported herein. The obtained compounds are transformed to pharmacologically attractive bridged tricyclic esters in a diastereospecific manner.