We found that chiral allylic acetals gave the corresponding aziridines in low yields and without stereoselectivity, while diastereoselective cyclopropanation of the same substrates has been reported [Mash, E. A.; Nelson, K. A. Tetrahedron 1987, 43, 679; Mash, E. A.; Hemperly, S. B.; Nelson, K. A.; Heidt, P. C.; Van Deusen, S. J. Org. Chem. 1990, 55, 2045].