G. Bringmann et al., THE ORTHO-HYDROXY-ORTHO'-FORMYL BIARYL LACTOL EQUILIBRIUM - QUANTUMCHEMICAL STUDIES ON STRUCTURE AND DYNAMICS/, Tetrahedron, 54(36), 1998, pp. 10691-10698
The equilibrium between the lactol-bridged biaryls 3 and the ring open
ed hydroxy aldehyde isomers 4 as well as their atropisomerization are
investigated by quantumchemical calculations. The suitability of semie
mpirical and different modern ab initio methods is validated by compar
ison with experimentally observed equilibria and crystallographic data
. It is shown that for the description of the equilibrium between 3 an
d 4 Hartree-Fock ab initio methods lead to a significant improvement c
ompared with semiempirical methods. Furthermore, the consideration of
solvent effects by using AM1-SM4, PM3-SM4 and PM3-SM3 gives satisfying
results in the description of the equilibrium investigated. (C) 1998
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