Cycloaddition reactions of nitrones with 4-methylene-5-morpholino-3-phenyl-4,5-dihydroisoxazole. Structure and stereochemical assignments of the products by nuclear magnetic resonance and X-ray analysis
Abstract
4-Methylene-5-morpholino-3-phenyl-4,5-dihydroisoxazole (1) reacts with nitrones (2) to give a mixture of diastereoisomeric cycloadducts, namely spiro[isoxazolidine-5,4′-isoxazolines](3) and (4). The structure and steric configuration of the spiro derivatives have been assigned on the basis of 1H and 13C NMR evidence and by X-ray analysis.