Cyclisations of azidoformates. Cyclisation of aryl azidoformates

Abstract

Phenyl azidoformates give benzoxazolones on ‘spray pyrolysis’ by direct nitrene attack at the ortho-position and α-naphthyl azidoformate gives a naphthoxazolone only by β-attack; biphenyl-2-yl azidoformate gives both 7-phenylbenzoxazolone and an azepine by nitrene attack of the adjacent ring while 2,6-dimethylphenyl azidoformate gives the endo-Diels–Alder dimer of 6-iso-cyanato-2,6-dimethylcyclohexa-2,4-dienone under the same conditions.