ENANTIOSELECTIVE SYNTHESIS OF 2-ISOXAZOLINES VIA ASYMMETRIC 1,3-DIPOLAR CYCLOADDITION OF NITRILE OXIDE TO ACHIRAL ALLYL ALCOHOL

The asymmetric 1,3-dipolar cycloaddition of a nitrile oxide to an achi ral allyl alcohol was achieved by the use of (R,R)-diisopropyl tartrat e as a chiral auxiliary. Treatment of the allyl alcohol with diethylzi nc and the tartrate, followed by the addition of diethylzinc and a hyd roximoyl chloride, afforded the corresponding (R)-2-isoxazolines with excellent enantioselectivity.