| Abstract
| - Cyclization of the N-dimethylphosphinoyl-2-methyl-3-aza-5-hexenyl radical has been studied atthe UB3LYP/6-31+G(d)//UB3LYP/6-31G(d) hybrid density functional level. The correspondingradical precursor has been synthesized and found to give cis/trans ratios of up to 10/1 in reductiveradical cyclizations. The relative energies of reactant and transition state conformers weredetermined. In discord with the Beckwith−Houk model, it has been found that chair-axial transitionstates, which lead to cis products, are lowest in energy, rationalizing the observed experimentaldiastereoselectivity.
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