SYNTHESES AND CHARACTERIZATION OF NEW (2S)-2-HYDROXY-1,4-OXAZIN-3-ONES DERIVED FROM BETA-AMINOALCOHOLS

The reactions of methyl glyoxylate hemiacetal 1 with 2-(methylamino)et hanol 2, (1R,2S)-(-)-ephedrine 3 and (1S,2S)-(+)-pseudoephedrine 4 pro vide the (2S)-2-hydroxy-1, 4-oxazin-3-ones 2a, 3a, 4a in good yield. T hey were characterized by H-1, C-13, NMR, and infrared and mass spectr oscopy. The structures of 2a and 3a were established by X-ray diffract ion. The configuration of C-2 (S) is demonstrated by H-1 NMR data and confirmed for compounds 2a and 3a by single-crystal X-ray diffraction studies. (C) 1996 John Wiley & Sons, Inc.