ARYLAZOMETHYLENETRIPHENYLPHOSPHORANES - INTRA MOLECULAR REACTIONS WITH ALDONITRONYL SUBSTITUENTS IN THE ORTHO POSITION WITH RESPECT TO THE AZOPHOSPHORANE GROUP

The title reactions begin with the attack on the aldonitronyl group by the nitrogen atom α to the ylidic carbon, to give, presumably, a cyclic species, which splits off a nitroso compound to afford indazolyl-2-methylenetriphenylphosphorane. In one case the primarily formed cyclic species underwent a further intra molecular cyclization to imidazo[1,2-b] indazole. © 1985.