title: Nazarov reactions intercepted by (4 + 3) cycloadditions with oxygen-substituted dienes.
abstract: The oxyallyl cation intermediate from the Lewis acid mediated Nazarov reaction of an allenyl vinyl ketone was intercepted by acyclic, 2-silyloxy-substituted butadienes by highly regioselective (4 + 3) cycloadditions. Stereoselectivity was often modest, but in some instances steric interactions were responsible for high selectivity. The results are consistent with concerted (4 + 3) cycloadditions. In many instances, the (4 + 3) products were susceptible to fragmentation or rearrangement in the presence of the Lewis acid.
authors.affiliation: Department of Chemistry, Dalhousie University, P.O. Box 15000, Halifax, Nova Scotia B3H 4R2, Canada.
authors.forename: François M
authors.initials: FM
authors.lastname: LeFort
authors.affiliation: Department of Chemistry, Dalhousie University, P.O. Box 15000, Halifax, Nova Scotia B3H 4R2, Canada.
authors.forename: Vinayak
authors.initials: V
authors.lastname: Mishra
authors.affiliation: Department of Chemistry, Dalhousie University, P.O. Box 15000, Halifax, Nova Scotia B3H 4R2, Canada.
authors.forename: Graham D
authors.initials: GD
authors.lastname: Dexter
authors.affiliation: Department of Chemistry, Dalhousie University, P.O. Box 15000, Halifax, Nova Scotia B3H 4R2, Canada.
authors.forename: Timothy D R
authors.initials: TD
authors.lastname: Morgan
authors.affiliation: Department of Chemistry, Dalhousie University, P.O. Box 15000, Halifax, Nova Scotia B3H 4R2, Canada.
authors.forename: D Jean
authors.initials: DJ
authors.lastname: Burnell