Toward the development of a structurally novel class of chiral auxiliaries: diastereoselective aldol reactions of a (1R,2S)-ephedrine-based 3,4,5,6-tetrahydro-2H-1,3,4-oxadiazin-2-one. - Casper DM; Burgeson JR; Esken JM; Ferrence GM; Hitchcock SR (Organic letters, 2002)