Heterocyclization of Enediynes Promoted by Sodium Azide: A Case of Ambiguity of X‑ray Data and Structure Revision

It
has been shown that contrary to the literature data the tandem
cyclization of (Z)-1-aryl-3-hexen-1,5-diynes promoted
by sodium azide results in the formation of the corresponding [1,2,3]­triazolo­[1,5-a]­pyridines, not 1H-benzo­triazole
derivatives. Apparently, incorrect structure elucidation made by previous
investigators originates from misinterpretation of X-ray data. A number
of new transformations of this type as well as X-ray and NMR experiments
are discussed.