title: Diels-Alder adducts of medium-ring carbocyclic dienes prepared by rearrangement of catalytically generated cyclic oxonium ylides.
abstract: The novel bicyclic and tricyclic systems dimethyl (4aS*,6S*)-6-methoxy-7-oxo-4a,5,6,7,8,9-hexahydro-2H-benzocycloheptene-3,4-dicarboxylate, C(16)H(20)O(6), (I), dimethyl (4aS*,6R*)-6-methoxy-7-oxo-4a,5,6,7,8,9-hexahydro-2H-benzocycloheptene-3,4-dicarboxylate, C(16)H(20)O(6), (II), (3aS*,9R*,10aS*,10bR*)-9-methoxy-2-oxa-1,3a,4,6,7,8,9,10,10a,10b-decahydro-3H-cyclohepta[e]indene-1,3,8-trione, C(14)H(16)O(5), (III), and (1S*,2R*,9S*,10aR*)-9-methoxy-8-oxo-1,2,3,5,6,7,8,9,10,10a-decahydrobenzocyclooctene-1,2-dicarboxylic acid, C(15)H(20)O(6), (IV), have been crystallographically characterized, allowing the determination of the relative configuration of the stereogenic centres. The poor quality of the dicarboxylic acid crystals necessitated the use of synchrotron radiation.
authors.affiliation: School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, England. claire.wilson@nott.ac.uk
authors.forename: C
authors.initials: C
authors.lastname: Wilson
authors.forename: J S
authors.initials: JS
authors.lastname: Clark
authors.forename: A L
authors.initials: AL
authors.lastname: Bate
authors.forename: A J
authors.initials: AJ
authors.lastname: Blake
authors.forename: T
authors.initials: T
authors.lastname: Grinter
authors.forename: S J
authors.initials: SJ
authors.lastname: Teat