title: Conformational effects in acid-mediated ring opening of epoxides: a prominent role of the oxirane Walsh orbital.
abstract: A kinetic study has been made of the BF(3)-mediated ring opening of two rigid conformers (alpha and beta) of m- and p-dimethyl-substituted homobenzoquinone epoxides spiro-linked with a twist-boat dibenzocycloheptene ring as compared with the conformationally mobile epoxides bearing diphenyl groups. The rates of the regioselective ring opening were dependent on the topological alignment of the dibenzocycloheptene ring as well as the substitution pattern of the quinone dimethyl groups, indicating pi-aryl participated orbital interaction with the vacant Walsh orbital of the oxirane ring.
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan. oshima@chem.eng.osaka-u.ac.jp
authors.forename: Takumi
authors.initials: T
authors.lastname: Oshima
authors.forename: Haruyasu
authors.initials: H
authors.lastname: Asahara
authors.forename: Emi
authors.initials: E
authors.lastname: Kubo
authors.forename: Saki
authors.initials: S
authors.lastname: Miyamoto
authors.forename: Kyoko
authors.initials: K
authors.lastname: Togaya