Isoxazolines, are versatile synthetic intermediates in the preparation of a variety of compounds with 1, 3-difunctional groups and are readily constructed via the 1, 3-dipolar cycloaddition of nitrile oxides 1 to olefins 2. 1 Although these cycloadditions display high regioselectivity, 2 it remains challenging to form optically pure isoxazolines via asymmetric cycloadditions. 3 For example, the isoxazoline nucleoside 3 (R) CH2OH, Y) 6- ...