SYNTHESIS OF SOME ISOXAZOLIDINE AND ISOXAZOLINE DERIVATIVES USING NITRONE-DERIVED (-)-MENTHONE VIA 1,3-DIPOLAR CYCLOADDITION WITH ALKENES, ALKYNES AND CYCLOALKENES

摘要

Cycloaddition reactions between a menthone-based chiral nitrone and alkenes or alkynes under microwave activation afforded a series of enantiopure cycloadducts in good yields and with high stereo selectivity. Removal of the chiral auxiliary under acid-catalysis led to a new series of isoxazolidines and isoxazolines with the control of one, two or three stereogenic centers.