title: Regio- and diastereoselective stepwise [8 + 3]-Cycloaddition reaction between tropone derivatives and donor-acceptor cyclopropanes.
abstract: A novel SnCl4-catalyzed [8 + 3]-cycloaddition reaction between tropone derivatives and donor-acceptor aminocyclopropanes is described. The process leads to the formation of amino-substituted tetrahydrocyclohepta[b]pyrans with complete regio- and diastereoselectivity. Density functional theory calculations suggest that the cycloaddition occurs stepwise through an aromatic zwitterionic intermediate.
authors.affiliation: Departamento de Química Orgánica I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid , 28040-Madrid, Spain.
authors.forename: Alexandra R
authors.initials: AR
authors.lastname: Rivero
authors.forename: Israel
authors.initials: I
authors.lastname: Fernández
authors.forename: Miguel Ángel
authors.initials: MÁ
authors.lastname: Sierra