The oxidative cyclization of the thiosemicarbazones of 4-piperidones (2) fu
rnished spiro piperidino-1,2,4-triazoles (3,4,5), while the pyrolysis of 5
led to spiro piperidinoaziridines (6). The new compounds were characterized
by IR and H-1 NMR spectral data. (C) 1999 John Wiley & Sons, Inc.