Type 1 Ring-Opening Reactions of Cyclopropanated 7‑Oxabenzonorbornadienes with Organocuprates

Abstract

For the first time, nucleophilic ring-openings of cyclopropanated 7-oxabenzonorbornadiene were investigated, providing a novel approach to the preparation of 2-methyl-1,2-dihydronaphthalen-1-ols. Satisfactory yields (up to 95%) were achieved using <i>n</i>-Bu₂CuCNLi₂ as the nucleophile and Et₂O as the solvent. The reaction demonstrated successful incorporation of primary, secondary, tertiary and aromatic nucleophiles, as well as ring-openings of substrates bearing arene substituents and C1-bridgehead substituents. A generalized mechanism for these transformations is also proposed