title: 13C and 1H NMR of 2,6-diaryl-1-hydroxy piperidin-4-one oximes; substituent effects on cis/trans ratio and conformational equilibria.
abstract: The reaction of substituted diarylidene acetones with hydroxylamine hydrochloride affords isomeric N-hydroxy diaryl piperidinone oximes as main products. The structures as well as conformational equilibria of these products were established by 1H and 13C NMR spectroscopy and further studied by variable temperature NMR. It was found that the cis/trans ratio of 2,6-substituted piperidine derivatives depended on the position of the substituent on the aromatic ring.
authors.affiliation: Instituto de Química, U. National Autonoma de Mexico, Circuito Exterior C. Universitaria, Coyoacán, Mexico D.F., México. maudiaz@servidor.unam.mx
authors.forename: E
authors.initials: E
authors.lastname: Díaz
authors.forename: H
authors.initials: H
authors.lastname: Barrios
authors.forename: F
authors.initials: F
authors.lastname: del Río Portilla
authors.forename: A
authors.initials: A
authors.lastname: Guzmán
authors.forename: J L
authors.initials: JL
authors.lastname: Aguilera
authors.forename: R
authors.initials: R
authors.lastname: Becerril
authors.forename: C K
authors.initials: CK
authors.lastname: Jankowski
authors.forename: W F
authors.initials: WF
authors.lastname: Reynolds
mesh_terms: D000096:Acetone / Q000737:chemistry; D019811:Hydroxylamine / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D010091:Oximes / Q000138:chemical synthesis / Q000737:chemistry*; D013237:Stereoisomerism; D013696:Temperature
chemical_list: D010091:Oximes; D000096:Acetone; D019811:Hydroxylamine