A facile stereoselective synthesis of 2-perfluoroalkyl-3a,4,5, 6-tetrahydroimidazo[ 1,5-b]isoxazoles

Methyl 2-perfluoroalkynoates 2 reacted readily with cyclic nitrones 1 via 1,3-dipolar cycloaddition at room temperature to give 2-perfluoroalkyl-3a,4,5,6-tetrahydroimidazo[1,5-b]isoxazoles 3 in good to excellent yields with high diastereoselectivity and regioselectivity.