A series of hetero 2,3-dispiro cyclohexanones has been prepared. The conformations of the syn and anti isomers were assessed in the solid state, in solution, and in the gas phase (the latter by molecular mechanics calculations). The results are discussed in the light of steric, dipole, and gauche interactions; steric contributions give evidence of controlling DELTAG(eq). On a different front, the syn/anti pairs were found to interconvert when heated in the presence of a catalytic amount of acid. Three representative examples of these chiral molecules were resolved and complete racemization was observed to result under the conditions of equilibration. A push-pull fragmentation of the cyclohexanone ring is proposed to account for these observations, with the tethered oniom ion-enol pair reclosing to reconstitute the original, although stereochemically scrambled, structure. The intervention of the thionium ion intermediates is less thermodynamically favorable than that of oxonium ions, as expected.