Brønsted acid-catalyzed annulation reaction of hydroxamic acids: synthesis of cyclopentane-fused isoxazolidines and their benzilic amide rearrangement

Abstract

Readily available hydroxamic acids were used to access challenging nitrones in the presence of H3PO4 as a Brønsted acid catalyst and engaged in intramolecular (3+2) annulation to make valuable cyclopentane-fused isoxazolidines with high yields and excellent diastereoselectivity.