derived mesylate was used to construct the side chain that was designed to afford the cyclohexene ring of coronafacic acid via intramolecular alkylation. Elimination of the mesylate proceeded with TBAF. The alkylation was achieved with t-BuOK in THF, and then hydrolysis afforded coronafacic acid, which upon condensation with unprotected l-isoleucine using ClCO2Bui furnished coronafacoyl-l-isoleucine, the