Pyrrolidine N-oxides bearing a 2-aryl substituent are known to rearrange with ring expansion to form tetrahydro-2H-1, 2-oxazines. Similar piperidine N-oxides have now been found to follow the same course, and for the kst time compounds with the hexahydro-l, 2- oxazepine ring system have been made available. The reactions were performed at 170'in dimethylacetamide and were accompanied by some loss of oxygen from the N-oxides. ...
