Methylene transfer from dimethyloxosulphonium methylide to N-arylsulphonylaziridines: stereospecific synthesis of N-arylsulphonylazetidines

Several 2-alkyl-, 2-aryl-, 2-benzyl-, 2,3-dialkyl- and 2,3-diaryl-N-arylsulphonylazetidines have been prepared in fair to good isolated yields through reaction of N-arylsulphonylaziridines with dimethyloxosulphonium methylide. Fused azetidines, however, could not be obtained through this procedure. The stereospecificity and generality of the reaction together with the ready accessibility of the required aziridines make this methodology attractive. Evidence supporting an addition–1,4-elimination mechanism, rather than one involving intermediacy of an azomethine ylide, is presented.