title: Asymmetric induction in 8π electrocyclizations. Design of a removable chiral auxiliary.
abstract: The pseudo C(2) symmetric trans diphenyl oxazoline group acts as an effective chiral auxiliary in the 8π, 6π tandem electrocyclization of a substituted tetraene 1-carboxylic acid. Assignment of absolute stereochemistry to the [4.2.0] bicyclooctadiene product supports a model in which both s-cis and s-trans conformations favor the transition states with the same helical twist. This assignment prefaces the development of analogs of SNF4435 C and D. These natural products demonstrate activity as androgen receptor antagonists and as multidrug resistance (mdr) reversal agents.
authors.affiliation: Department of Chemistry, Stony Brook University, Stony Brook, New York 11733, USA.
authors.forename: Keunsoo
authors.initials: K
authors.lastname: Kim
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Lauher
authors.forename: Kathlyn A
authors.initials: KA
authors.lastname: Parker
mesh_terms: D001688:Biological Products / Q000737:chemistry; D003500:Cyclization; D004583:Electrons; D008958:Models, Molecular; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D001688:Biological Products