title: Enantioselective Nazarov Cyclization Catalyzed by a Cinchona Alkaloid Derivative.
abstract: Nucleophilic catalysts for a 1,6 addition/Nazarov cyclization/elimination sequence were evaluated for their ability to induce enantioselectivity in the electrocyclization step. Of the tertiary amines examined, it was found that a cinchona alkaloid derivative was able to generate substituted 5-hydroxy γ-methylene cyclopentenones with excellent enantioselectivity. The study results suggest that successful cyclization depends upon the ability of the dienyl diketone substrate to readily adopt ans-cisconformation.
authors.affiliation: Department of Chemistry, University of Rochester, Rochester, New York 14627, United States.
authors.forename: Yu-Wen
authors.initials: YW
authors.lastname: Huang
authors.affiliation: Department of Chemistry, University of Rochester, Rochester, New York 14627, United States.
authors.forename: Alison J
authors.initials: AJ
authors.lastname: Frontier
keywords: Nazarov cyclization; cinchona alkaloid; enantioselective