title: Useful catalytic enantioselective cationic double annulation reactions initiated at an internal π-bond: method and applications.
abstract: The 1:1 complex of o,o'-dichloro-R-BINOL and SbCl5 initiates the enantioselective cationic polycyclization of polyunsaturated substrates at a predictable π-bond which may be either terminal or, as shown herein, internal. The extension of this powerful construction to internal π-bonds expands the scope of this method and opens up very short pathways to numerous chiral polycyclic molecules, including natural products and their analogues. Especially simple synthetic routes are disclosed that provide access to dysideapalaunic acid, dehydroabietic acid, and epipodocarpic acid and illustrate the value of this enantioselective approach.
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University , Cambridge, Massachusetts 02138, United States.
authors.forename: Karavadhi
authors.initials: K
authors.lastname: Surendra
authors.forename: Goreti
authors.initials: G
authors.lastname: Rajendar
authors.forename: E J
authors.initials: EJ
authors.lastname: Corey
mesh_terms: D002384:Catalysis; D002412:Cations / Q000737:chemistry; D003500:Cyclization; D015394:Molecular Structure; D011083:Polycyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D002412:Cations; D011083:Polycyclic Compounds