Theoretical calculations at the B3LYP/6-31G(d) level have been carried out on the isomerization of cyclictri-glycine into the corresponding tri-cyclol. The results confirmed that the cyclol hypothesis was untenable both from a thermodynamic as well as from a kinetic point of view.
Alkorta, I., Sanchez-Sanz, G., Trujillo, C., Azofra Mesa, L. M., & Elguero, J. (2012). A theoretical reappraisal of the cyclol hypothesis. Structural Chemistry, 23(3), 873 - 877. https://doi.org/10.1007/s11224-012-9947-8