II. 1,3-Dipolar cycloadditions to unsaturated boronic esters. Synthesis of borylated 2-isoxazolines. Conversion of some cycloadducts to 5-hydroxy-2-isoxazolines, 5-hydroxymethyl-2-isoxazolines and isoxazoles
2-isoxazolines was prepared by 1,3-cycloaddition reactions of nitrile oxides to vinyl- and allylboronic esters. The influence of substituents on the reactivity, the regio- and stereoselectivity was examined and some examples of cycloadduct oxidation were described.