In 2009, Brown et. Al showed that a naphthalene-derived structure catalyzed one type of this reaction, yielding the highest enantioselectivity to date induced by the chiral cavity of a supramolecular assembly. Degenerate forms of this reaction are responsible for the single peak at 4.2 ppm of the fluxional molecule bullvalene. This observation is due to diradical transition state that preserves orbital symmetry. Proceeding only when surpafacial on all components of the reaction, this reaction also occurs in aza and oxy 
In 2009, Brown et. Al showed that a naphthalene-derived structure catalyzed one type of this reaction, yielding the highest enantioselectivity to date induced by the chiral cavity of a supramolecular assembly. Degenerate forms of this reaction are responsible for the single peak at 4.2 ppm of the fluxional molecule bullvalene. This observation is due to diradical transition state that preserves orbital symmetry. Proceeding only when surpafacial on all components of the reaction, this reaction also occurs in aza and oxy varieties, the latter of which produces an enol or enolate product that does not equilibrate to the regioisomer. Its diradical mechanism is both concerted and pericyclic, explaining the 300 Celsius reaction conditions needed for this process to occur. For 10 points, name this [3,3] sigmatropic thermal isomerization of a 1,5-diene yielding a regioisomeric 1,5-diene that is not the Claisen rearrangement.
In 2009, Brown et. Al showed that a naphthalene-derived structure catalyzed one type of this reaction, yielding the highest enantioselectivity to date induced by the chiral cavity of a supramolecular assembly.
Cope rearrangement