title: Lewis acid tuned facial stereodivergent HDA reactions using beta-substituted N-vinyloxazolidinones.
abstract: The [4 + 2] acido-catalyzed heterocycloaddition between new beta-substituted N-vinyl-1,3-oxazolidin-2-ones (with R' = Me, Ar, CH2 Ar) and beta,gamma-unsaturated alpha-ketoesters (R = Ar) afforded heteroadducts with high levels of endo and facial selectivities. A complete reversal of facial differentiation was achieved by varying the Lewis acid, leading to the stereoselective formation of either endo-alpha or endo-beta adducts. [reaction: see text].
authors.affiliation: UMR 6011 CNRS-Université du Maine, Laboratoire de Synthèse Organique (UCO2M), Faculté des sciences, Avenue Olivier Messiaen, 72085 Le Mans Cedex 9, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Gohier
authors.forename: Keltoum
authors.initials: K
authors.lastname: Bouhadjera
authors.forename: Djibril
authors.initials: D
authors.lastname: Faye
authors.forename: Catherine
authors.initials: C
authors.lastname: Gaulon
authors.forename: Vincent
authors.initials: V
authors.lastname: Maisonneuve
authors.forename: Gilles
authors.initials: G
authors.lastname: Dujardin
authors.forename: Robert
authors.initials: R
authors.lastname: Dhal