ENANTIOSELECTIVE SYNTHESIS OF -3-AMINO-5-(MORPHOLINOMETHYL)-1,3-OXAZOLIDIN-2-ONE - AN INTRAMOLECULAR COMPETITION FOR OXIRANE VERSUS AZETIDINE RING FORMATION

Using C-3 chiral synthon: (S)-2,2-dimethyl-1,3-dioxolan-4-ylmethanol ( 5) or (R)-4-chloromethyl-2,2-dimethyl-1,3-dioxolane (6) synthesis of t he title compound was performed. The key step of the synthesis consist ed in the oxirane ring closure in (S)-3-morpholino-1,2-diol (9). The p aralel reaction, formation of the azetidinium moiety, was era mined a nd the structure of the resulting 2-hydroxy-4-azonia-7-oxaspiro[3.5]no nane (11) was established by single crystal X-ray analysis.