SYNTHESIS OF HOMOCHIRAL 3-OXA-2,7-DIAZABICYCLO[3.3.0]OCTANES FROM AMINO-ACIDS BY INTRAMOLECULAR 1,3-DIPOLAR CYCLOADDITION OF NITRONES

N-Allylamino alcohols 0 were prepared from amino acids by various methods. Swern oxidation of 9 afforded aldehydes 11. By reaction of 11 with N-alkylhydroxylamines nitrone intermediates 4 were formed which spontaneously underwent an intramolecular 1,3-dipolar cycloaddition to yield the bicyclic compounds 6. The cycloaddition proceeds diastereoselectively furnishing homochiral compounds 6 from homochiral starting materials. The structure of 6aA was confirmed by X-ray structural analysis.