title: Alpha-alkenoyl ketene S,S-acetal-based multicomponent reaction: an efficient approach for the selective construction of polyfunctionalized cyclohexanones.
abstract: A versatile multicomponent reaction based on the new four-carbon synthons alpha-alkenoyl ketene S,S-acetals 1 has been developed. This three-component reaction of readily available alpha-alkenoyl ketene S,S-acetals 1 with aldehydes 2 and active methylene compounds 3 proceeds smoothly in acidic medium (glacial acetic acid in tetrahydrofuran) to give various polyfunctionalized cyclohexanones 4, 5, and 6 in a highly regio- and diastereoselective manner with good to excellent yields. The reaction can tolerate a broad range of substituents in the three components involved and is proposed to proceed via a tandem Knoevenagel-intermolecular Michael-intramolecular Michael sequence. As an extension of the synthetic application of polyfunctionalized cyclohexanones obtained, unsymmetrical biaryls 7 were synthesized in almost quantitative yields by simple transformations of the corresponding cycloadducts 6.
authors.affiliation: Department of Chemistry, Northeast Normal University, Changchun 130024, PR China.
authors.forename: Yuhui
authors.initials: Y
authors.lastname: Ma
authors.forename: Mang
authors.initials: M
authors.lastname: Wang
authors.forename: Dan
authors.initials: D
authors.lastname: Li
authors.forename: Bahargul
authors.initials: B
authors.lastname: Bekturhun
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.forename: Qun
authors.initials: Q
authors.lastname: Liu
mesh_terms: D000080:Acetals / Q000737:chemistry*; D019342:Acetic Acid / Q000737:chemistry; D000447:Aldehydes / Q000737:chemistry; D000475:Alkenes / Q000737:chemistry*; D003512:Cyclohexanones / Q000138:chemical synthesis* / Q000737:chemistry; D005030:Ethylenes / Q000737:chemistry*; D005663:Furans / Q000737:chemistry; D007659:Ketones / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D015394:Molecular Structure; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
chemical_list: D000080:Acetals; D000447:Aldehydes; D000475:Alkenes; D003512:Cyclohexanones; D005030:Ethylenes; D005663:Furans; D007659:Ketones; C008223:ketene; D019342:Acetic Acid