title: An approach to a chiral cycloalkanone-mediated asymmetric epoxidation of stilbene with oxone.
abstract: Chiral and C2-symmetric seven-membered cycloalkanones 2--6 bearing 1,2-diphenylethane-1,2-diamine and cyclohexane-1,2-diamine backbones were synthesized and evaluated their asymmetry inductive behaviours in an asymmetric epoxidation of stilbene with oxone. Although the reaction of the ketones 2 and 3 of a 1,2-diphenylethane-1,2-diamine backbone gave stilbene oxide in trace to 31% yield, those of the ketones 4-6 of a cyclohexane-1,2-diamine backbone gave the epoxide in satisfactorily high yield up to 98%. It is noteworthy that both reactions with use of stoichiometric and substoichiometric amounts of a ketone 4 gave the epoxide in the essentially same enantioselectivity, 17 and 18%. Eleven-membered cyclic ketones 7 and 8 bearing a binaphthalene backbone were also synthesized and examined their behaviours, while the enantioselectivity turned out to be marginal.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Kyoto University, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Matsumoto
authors.forename: K
authors.initials: K
authors.lastname: Tomioka
mesh_terms: D001381:Azepines / Q000737:chemistry*; D004852:Epoxy Compounds / Q000138:chemical synthesis*; D007202:Indicators and Reagents; D007659:Ketones / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D013055:Spectrophotometry, Infrared; D013267:Stilbenes / Q000737:chemistry*; D013464:Sulfuric Acids / Q000737:chemistry*
chemical_list: D001381:Azepines; D004852:Epoxy Compounds; D007202:Indicators and Reagents; D007659:Ketones; D013267:Stilbenes; D013464:Sulfuric Acids; C048813:potassium peroxymonosulfuric acid