Abstract
The diastereoselectivity in the cycloaddition reactions of several mono- and disubstituted alkenes with a (-)norephedrine-derived methylenenitrone has been investigated. The stereochemical analysis of the addition products (i.e., isoxazolidines) has been carried out by X-ray, NMR, and chemical conversions. The NMR spectra of the isoxazolidines at low temperatures indicated the presence of either a single or a predominant invertomer. The stereochemistry of the invertomers and nitrogen inversion barriers are determined using complete line-shape analysis and their dependence on solvent is discussed. Copyright (C) 2008 John Wiley & Sons, Ltd.