Working three shifts: Polyconjugated δ-diketones are formed stereoselectively in high yields by the gold-catalyzed rearrangement of 1,6-diyn-3-yl esters. This cascade involves a 1,3-sigmatropic acyloxy shift, a 5-exo-dig cyclization of the resulting allenyne, and an unprecedented 1,5-sigmatropic shift of an acyl fragment. The usefulness of the products was shown by an efficient acid-catalyzed transformation into a complex polycyclic framework.
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Lebœuf et al. (2011) studied this question.