Lewis Acid Promoted Reactions of 11-Methylenepentacyclo(5.4.0.02,6.03,10.05,9)undecan-8-one and Pentacyclo(5.4.0.02,6.03,10.05,9)undecan-8-one with Ethyl Diazoacetate

摘要

The reaction of pentacyclo undecane-8,11-dione with ethyl diazoacetate (EDA, 1equiv) in the presence of F3B.OEt2, when performed at -78 C, afforded three products: diethyl 3,6-dioxopentacyclo tridecane-2,7-dicarboxylate, ethyl 2,6-dioxopentacyclo-dodecane-3-carboxylate (7.4%), and a novel heterocyclic compound, (31%), whose structure was established by X-ray structural analysis. Keywords: Ring homologation reactions, Substituted pentacycloundecanes, Regioselectivity, Ring expansion. (jes)