Reactions of oxaziridines with nucleophiles and reducing agents

4 Reactions of oxaziridines with nucleophiles and reducing agents 

The oxaziridine ring itself is stable towards alkali there is, for instance, no substitutive ring opening by hydroxyl ions as in oxiranes. 2-r-Butyl-3-phenyloxaziridine (56) is not attacked by methoxide ion in methanol during 12 h at room temperature 3-isopropyl-2-r-octyloxaziridine does not react at room temperature with either solid potassium hydroxide or potassium methoxide solution (57JA5739). 

In some cases, especially in the presence of strongly electron attracting substituents, isomerization to acid amides has been observed, probably preceded by deprotonation at ring carbon. Even (56), known for its stability towards common alkali, undergoes this rearrangement when a lithium amide is used as the base (80JOC1489). 

however, hydrogen is present in the a-position of the iV-alkyl substituent, 2-alkyl-oxaziridines are easily decomposed by alkali. Base attack on this H atom effects 1,2-elimination at the C—N bond. From (86) and aldimine (87) forms, and a mixture of ammonia and two carbonyl compounds is finally obtained, one of them containing the carbon atom of the original oxaziridine ring, the other originating from the IV-alkyl group (57JA5739). 

The decomposition of an oxaziridine by brucine, originally assumed to be a deoxygenation, proved to be a base-catalyzed decomposition (79TL3353). 

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S.08.3.1.4 Reactions of oxaziridines with nucleophiles and reducing agents... 

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