The reaction of the 3,4-O-isopropylidene-l-(S)-erythrulose with hydroxylamine, followed by treatment of the resulting mixture of (E)- and (Z)-oximes with acetone and an acid catalyst, afforded two crystalline chiral compounds. Through X-ray diffraction analysis, these products were identified as a double acetonide derived from the (E)-oxime and a cyclic nitrone derived from the (Z)-oxime. The additions