title: Asymmetric epoxidation of cis-alkenes mediated by iminium salts: highly enantioselective synthesis of levcromakalim.
abstract: [reaction: see text] A range of cis-substituted olefins has been epoxidized with a new dihydroisoquinolinium salt catalyst, using tetraphenylphosphonium monoperoxysulfate as the stoichiometric oxidant, giving ee's of up to 97%. The reaction has been used as the key step in an enantioselective synthesis of the antihypertensive agent levcromakalim.
authors.affiliation: Department of Chemistry, Loughborough University, Loughborough, Leicestershire LE11 3TU, England. p.c.b.page@lboro.ac.uk
authors.forename: Philip C Bulman
authors.initials: PC
authors.lastname: Page
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Buckley
authors.forename: Harry
authors.initials: H
authors.lastname: Heaney
authors.forename: A John
authors.initials: AJ
authors.lastname: Blacker