title: Basic and reductive sulfone-directed ring-opening reactions of difluorinated oxa[2.2.1]bicycloheptanes.
abstract: Phenylsulfenyl chloride reacts with racemic endo Diels-Alder adduct 4 (DEC = CONEt(2)) to afford lactone 8, which can be reduced and protected in a series of high-yielding steps. Key sulfone 10 can be ring opened under strong base conditions to afford vinyl sulfone 11. Attempted desulfonation resulted in the formation of a monofluoroalkene, but a direct desulfonation/eliminative ring opening with strain relief delivered highly functionalized monocyclic species 16. [reaction: see text]
authors.affiliation: Syngenta, Ltd., Jealott's Hill International Research Centre, Bracknell, Berks RG42 6ET, United Kingdom.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Crowley
authors.forename: John
authors.initials: J
authors.lastname: Fawcett
authors.forename: Benson M
authors.initials: BM
authors.lastname: Kariuki
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Moralee
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Percy
authors.forename: Vittoria
authors.initials: V
authors.lastname: Salafia