Table 1.

Calculated relative energies (in kcal/mol) in the gas phase at the HF/6 − 31 + G(d, p) level of theory

Compound	Relative energy
Reactant, IIa	0
5,4-shift product, VIa	−59.32
5,6-shift product, Va	−53.38
5,6-arene oxide, IIIa	−28.80
5,6-shift TS, VII	0.63
5,4-shift TS, VIII	3.12