title: Gassman's intramolecular [2 + 2] cationic cycloaddition. formal total syntheses of raikovenal and epi-raikovenal.
abstract: The first intramolecular version of Gassman's cationic [2 + 2] cycloaddition employing vinyl acetals tethered to an unactivated olefin and its application in the formal syntheses of raikovenal and epi-raikovenal are described.
authors.affiliation: Division of Pharmaceutical Sciences and Department of Chemistry, Rennebohm Hall, 777 Highland Avenue, University of Wisconsin, Madison, Wisconsin 53705-2222, USA.
authors.forename: Changhong
authors.initials: C
authors.lastname: Ko
authors.forename: John B
authors.initials: JB
authors.lastname: Feltenberger
authors.forename: Sunil K
authors.initials: SK
authors.lastname: Ghosh
authors.forename: Richard P
authors.initials: RP
authors.lastname: Hsung
mesh_terms: D000080:Acetals / Q000737:chemistry*; D000475:Alkenes / Q000737:chemistry*; D002412:Cations / Q000737:chemistry; D018360:Crystallography, X-Ray; D003500:Cyclization; D008958:Models, Molecular; D015394:Molecular Structure; D011084:Polycyclic Aromatic Hydrocarbons / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D014753:Vinyl Compounds / Q000737:chemistry*
chemical_list: D000080:Acetals; D000475:Alkenes; D002412:Cations; D011084:Polycyclic Aromatic Hydrocarbons; D014753:Vinyl Compounds; C529925:epi-raikovenal; C529926:raikovenal