Stereochemistry of the oxidation of imines derived from substituted cyclohexanones: axial vs equatorial attack and evidence for delivery by an adjacent hydroxyl group.
A set of conformationally biased imines derived from substituted cyclohexanones and benzylamine or diphenylmethylamine, respectively, were oxidized to the corresponding oxaziridines. The structures of the oxaziridines were determined via NMR comparison of two series of differently N-substituted oxaziridines. Thus, those compounds having an axially disposed nitrogen substituent displayed an upfield-shifted axial proton in a 1,3-relationship to the oxaziridine nitrogen in the N-diphenylmethyl series relative to the N-benzyl compounds. Analysis of the products obtained from these reactions suggests that (1) adjacent hydroxyl groups favor syn oxidant addition and (2) imines containing adjacent methoxy groups preferentially undergo attack anti to the resident alkoxy substituent.
Wang
Y
Y
Department of Medicinal Chemistry, University of Kansas, Lawrence 66045-2506, USA.
Chackalamannil
S
S
Aubé
J
J
D003512:Cyclohexanones / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry; D007097:Imines / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010084:Oxidation-Reduction; D013237:Stereoisomerism
D003512:Cyclohexanones; D007097:Imines; D017665:Hydroxyl Radical