Conformation of some sparteine N-16 oxides revisited
摘要:
Sparteine N-16 oxides were thought to occur in all chair conformations with cis fusion between their C and D rings. NMR spectral analysis made possible indication of the chair-chair-boat-chair form with cis fassion of C, D rings for sparteine, 2-phenyl- and 2-methylsparteine N-16 oxides. Molecular energy found by means of DFT, Hartree-Fock, AM1, PM3 methods supported this new shape of bisquinolizidine skeleton. (C) 2002 Elsevier Science B.V. All rights reserved.
New potentially biologically active N-bromobenzyl derivatives of α-isosparteine and 2-methylsparteine were
obtained. Newly obtained compounds were characterized by IR and NMR spectroscopy. The structure of the new compounds
in solution was proposed
Tetrahedrally distorted complexes of alpha-isosparteine, beta-isosparteine and 2-methylsparteine with FeCl2 have been synthesised. Crystal structures of these complexes are reported and compared with the structure of (-)-sparteine analogue. Coordination to Fe(II) center in beta-isosparteine and 2-methylsparteine brings about an inversion at the N16 nitrogen and change in configuration at the ring junction from trans to cis, accompanied by a change in the C-ring conformation from boat to chair. The all-chair alpha-isosparteine skeleton remains unchanged upon complexation. Structural parameters of the complexes are investigated using Becke three-parameter hybrid exchange functional combined with the Lee-Yang-Parr correlation functional (B3LYP) with 6-31G and 6-311G basis sets applied for geometry optimizations. (C) 2010 Elsevier B.V. All rights reserved.
Boczon, Wladyslaw, Polish Journal of Chemistry, 1981, vol. 55, # 2, p. 339 - 351
作者:Boczon, Wladyslaw
DOI:——
日期:——
Conformation of some sparteine N-16 oxides revisited
Sparteine N-16 oxides were thought to occur in all chair conformations with cis fusion between their C and D rings. NMR spectral analysis made possible indication of the chair-chair-boat-chair form with cis fassion of C, D rings for sparteine, 2-phenyl- and 2-methylsparteine N-16 oxides. Molecular energy found by means of DFT, Hartree-Fock, AM1, PM3 methods supported this new shape of bisquinolizidine skeleton. (C) 2002 Elsevier Science B.V. All rights reserved.