Synthesis, spectral and computational studies of some N-acyl-t(3)-isopropyl-r(2),c(6)-bis-2'-furylpiperidin-4-one oximes.
Four N-acyl-t(3)-isopropyl-r(2),c(6)-bis-2'-furylpiperidin-4-one oximes 1-4 were synthesized and the high resolution (1)H and (13)C NMR spectra have been recorded at various temperatures and analyzed. The spectra reveal the presence of two rotameric forms (syn and anti) in solution. (1)H-(1)H COSY and (1)H-(13)C COSY spectra have been recorded to assist the assignment of the signals for the syn and anti isomers of 1-4. Coupling constants predict an equilibrium mixture of boat form B(1) and alternate chair form CA for 1-4. The effect of varying the substituents at nitrogen and at C(4) on the (1)H and (13)C chemical shifts has been analyzed in detail. The molecular structures of the N-acyl derivatives 1-4 were also determined using AM1 Hamiltonian and the results have been compared to the results derived from spectral studies. Mass spectra have also been recorded for 1-4.
Manimekalai
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Department of Chemistry, Annamalai University, Annamalainagar, Tamil Nadu, India. profmeka1@gmail.com
Sivakumar
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D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods*; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D010091:Oximes / Q000737:chemistry*; D010880:Piperidines / Q000737:chemistry*
D010091:Oximes; D010880:Piperidines