A new approach toward the bicyclo[3.2.1]octenes via a carbocation-based cyclization from unusually functionalized seven-membered ring precursors

A base-promoted 1,5-ester shifting rearrangement reaction has been developed to access unusually functionalized seven-membered ring precursors, which could be further successfully transformed into bicyclo[3.2.1]octenes by directly closing one-carbon bridge via a key carbocation-based cyclization, providing a new and efficient route to the core of many natural products and their analogs.