title: Catalytic highly asymmetric 1,5(6)-selective cyclization reaction of α-hydroxyimino cyclic ketones: direct approach to ring-fused hydroxyimino dihydropyrans.
abstract: Herein, we have disclosed a catalytic asymmetric 1,5(6)-selective Michael/cyclization reaction of α-hydroxyimino cyclic ketones with γ,β-unsaturated α-keto esters. Unlike the previous catalytic strategies, this reaction provides a convenient 1,5(6)-selective asymmetric pathway to access synthetically useful ring-fused dihydropyrans. In general, high levels of yield, enantio- and diastereoselectivity (up to 99% yield, >99% ee and >20 : 1 dr) were obtained.
authors.affiliation: Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Institute of Biochemistry and Molecular Biology, Lanzhou University, Lanzhou, 730000, China.
authors.forename: Luping
authors.initials: L
authors.lastname: Liu
authors.forename: Dekui
authors.initials: D
authors.lastname: Zhang
authors.forename: Panpan
authors.initials: P
authors.lastname: Zhang
authors.forename: Xianxing
authors.initials: X
authors.lastname: Jiang
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
mesh_terms: D002384:Catalysis; D003500:Cyclization; D007659:Ketones / Q000737:chemistry*; D010091:Oximes / Q000138:chemical synthesis* / Q000737:chemistry; D011714:Pyrans / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D007659:Ketones; D010091:Oximes; D011714:Pyrans