Applications of N-phosphinoyloxaziridines in the conversion of alkenes to epoxides and esters to ?a-hydroxyesters

N-Phosphinoyloxaziridines possessing an activating 3-CF3 substituent oxidise alkenes to epoxides at 35-45°C. Esters can be oxidised to á-hydroxyesters via their lithium enolates by various 3-subsituted N-phosphinoyloxaziridines. Stereoselectivity is observed in both these oxidations.