Palladium-catalyzed ring-opening reactions of cyclopropanated 7-oxabenzonorbornadiene with alcohols

Palladium-catalyzed ring-opening reactions of cyclopropanated 7-oxabenzonorbornadiene derivatives using alcohol nucleophiles were investigated. The optimal conditions were found to be 10 mol % PdCl(2)(CH(3)CN)(2) in methanol, offering yields up to 92%. The reaction was successful using primary, secondary and tertiary alcohol nucleophiles and was compatible with a variety of substituents on cyclopropanated oxabenzonorbornadiene. With unsymmetrical C1-substituted cyclopropanated 7-oxabenzonorbornadienes, the regioselectivity of the reaction was excellent, forming only one regioisomer in all cases.