title: Photochemical pinacol rearrangements of unsymmetrical diols.
abstract: The photochemical pinacol reaction of a series of nonsymmetrical 9-fluorenyl-substituted vic-diols was investigated and compared with their acid-catalyzed thermal reaction. Unlike the thermal reaction, the radiation-induced processes involve only fluorenyl cations, as is reflected in differences of product distribution between the two reactions. From the product studies, substituent migratory aptitudes are reversed in the photochemical process, suggesting that kinetic control takes place under neutral conditions unlike the acid-catalyzed thermal reactions. The presence of fluorenyl cation intermediates and their lifetimes were established by laser flash spectroscopy studies.
authors.affiliation: Department of Chemistry, York University, Toronto, Ontario M3J 1P3, Canada.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Mladenova
authors.forename: Gurmit
authors.initials: G
authors.lastname: Singh
authors.forename: Austin
authors.initials: A
authors.lastname: Acton
authors.forename: Lie
authors.initials: L
authors.lastname: Chen
authors.forename: Olga
authors.initials: O
authors.lastname: Rinco
authors.forename: Linda J
authors.initials: LJ
authors.lastname: Johnston
authors.forename: Edward
authors.initials: E
authors.lastname: Lee-Ruff