Automerization ofan Enediyne via a Symmetrical <i>p</i>‑Benzyne DiradicalIntermediate

Automerization is defined as a rearrangement reaction that yields a degenerate form of the starting material. We now report that cyclohexeno[3,4]cyclodeca-1,5-diyne-3-ene rearranges to its automer, via a <i>D</i>_2h-symmetric <i>p</i>-benzyne intermediate. The NMR evidence is that when the enediyne is heated to 75 °C in DMSO with either LiI or NaNO₃ as possible nucleophile, the enediyne is consumed only in the presence of LiI, whereas it remains “unchanged” in the presence of NaNO₃.