MINDO/3 Calculations on the Acid-Catalyzed Ring Opening of Oxaziridine

MINDO/3 semiempirical molecular orbital calculations were performed on oxaziridine and four protonated derivatives (N-protonated, O-protonated cis, O-protonated trans, and edge protonated). For the first three of these, further calculations were done along reaction coordinates, leading to ring cleavage at each of the three possible bonds. The results are interpreted to favor a mechanism for the ring opening of N-alkyloxaziridines which goes through the O-protonated intermediate, while in a C-phenyl derivative a mechanism with an N-protonated intermediate is favored. Reaction coordinates for the intramolecular interconversion of the four protonated derivatives were also calculated.