CATALYTIC ASYMMETRIC 1,3-DIPOLAR CYCLOADDITION OF NITRILE OXIDES TO AN ACHIRAL ALLYL ALCOHOL UTILIZING DIISOPROPYL TARTRATE AS A CHIRAL AUXILIARY

The catalytic asymmetric 1,3-dipolar cycloaddition of nitrile oxides t o an achiral allyl alcohol was achieved by the use of a catalytic amou nt of diisopropyl (R,R)-tartrate as a chiral auxiliary to afford the c orresponding (R)-2-isoxazolines with high enantioselectivity. In order to realize reproducible higher stereoselection, the addition of a sma ll amount of ethereal compound such as 1,4-dioxane was crucial.