title: Investigation of a stereoselective co-mediated rearrangement reaction.
abstract: A stereocontrolled approach to alpha-alkyl beta-alkynyl cyclohexanones is reported through a Lewis acid mediated rearrangement reaction of enol ethers bearing an Co-alkyne moiety. The reaction proceeds with high levels of stereoselectivity in the presence of Ti- and B-Lewis acids to provide a range of alpha,beta-disubstituted cyclohexanones in high yield although the products are prone to epimerization at the alpha-position in the presence of the B-promoter system. The potential for an enantioselective variant of this process is outlined, and a rationale for the observed stereochemical trends and detailed structural analyses of the ketone products are described.
authors.affiliation: Department of Chemistry, University of Sheffield, Brook Hill, UK.
authors.forename: David R
authors.initials: DR
authors.lastname: Carbery
authors.forename: Serge
authors.initials: S
authors.lastname: Reignier
authors.forename: Neil D
authors.initials: ND
authors.lastname: Miller
authors.forename: Harry
authors.initials: H
authors.lastname: Adams
authors.forename: Joseph P A
authors.initials: JP
authors.lastname: Harrity