dyotropic rearrangement

https://doi.org/10.1351/goldbook.D01879
An uncatalysed process in which two σ-bonds simultaneously migrate intramolecularly, e.g.
D01879.png
Source:
PAC, 1994, 66, 1077. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1108 [Terms] [Paper]