“Zip”Ring Expansion

Ring expansion reaction is one of the excellent methods for construction of medium- and large sized cyclic compounds. In present review, the so-called “zip” ring expansion has been focussed to synthesize carbocyclic or heterocyclic compounds. The reaction proceeds under a basic media (or radical process) via one-pot two-steps sequence from α, α-disubstituted cyclic ketones with a nucleophilic side chain;i) addition of intramolecular nucleophile (or radical) to carbonyl function to construct a bicyclo[m.n.0] skeletal intermediate;ii) cleavage of bridged bond to afford [m+n]-membered products.