Resumen de Microscale Synthesis of a Diphenylisoxazoline by a 1,3-Dipolar Cycloaddition
William B. Martin, Laura J. Kateley, Dawn C. Wiser, Catherine A. Brummond
This microscale synthesis of a diphenylisoxazoline gives students an opportunity to prepare and examine the heterocyclic product of a pericyclic 1,3-dipolar addition reaction analogous to a Diels-Alder reaction. Two reaction pathways are proposed, one leading to 3,4-diphenylisoxazoline and the other to 3,5-diphenylisoxazoline. The 1H NMR spectrum of the actual product is used to determine its structure and thus the reaction pathway. The proposed products have diasteriotopic hydrogens that are readily observed in the 1H NMR spectra. Molecular modeling also is used to predict which product is more probable and to offer a likely explanation for the regioselectivity of the reaction.
