title: Regiochemical control in intramolecular cyclization of methylene-interrupted epoxydiols.
abstract: [reaction: see text] Methylene-interrupted epoxydiols have multiple regiochemical routes for cyclization. The 5-exo process is the most prevalent under acidic conditions. However, the regioselectivity can be controlled by the appropriate choice of acid promoter and pendant groups adjacent to the epoxide. The 5-exo product is obtained exclusively without the presence of a carbocation-stabilizing pendant group. Alkenyl and thiophenyl groups adjacent to the epoxide alter the regioselectivity and enable access to the 5-endo tetrahydrofuran and 6-endo tetrahydropyran products.
authors.affiliation: Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: R S
authors.initials: RS
authors.lastname: Narayan
authors.forename: M
authors.initials: M
authors.lastname: Sivakumar
authors.forename: E
authors.initials: E
authors.lastname: Bouhlel
authors.forename: B
authors.initials: B
authors.lastname: Borhan