S. Tomoda et T. Senju, Origin of pi-facial diastereoselection in hydride reduction of piperidones. The importance of ground-state effects, CHEM LETT, (7), 1999, pp. 625-626
The exterior frontier orbital extension model(the EFOE Model) strongly sugg
ested that the ground-state conformation (steric effects) and the anisotrop
ic frontier orbital (LUMO) extension over pi-faces may be the origin of the
pi-facial diastereoselection in hydride reductions of substituted piperido
nes.