Construction of Cyclopenta[b]naphthalenol Frameworks by Weinreb Amide‐Directed Umpolung Ring Opening of Methylenecyclopropanes

Abstract A cascade cyclization from Weinreb amide‐tethered methylenecyclopropanes and alkynes has been disclosed in this paper, which extends the umpolung ring opening of methylenecyclopropanes, giving a synthetic approach for the construction of polycyclic cyclopenta[ b ]naphthalenol framework. In the protocol, four carbon‐carbon bonds and two carbocycles are formed without the use of transition metals, providing a tool for constructing the structure‐related polycyclic compounds. magnified image